Publications by authors named "Patricia Crock"

41 Publications

Growth Hormone Treatment Promotes Remote Hippocampal Plasticity after Experimental Cortical Stroke.

Int J Mol Sci 2020 Jun 26;21(12). Epub 2020 Jun 26.

School of Biomedical Sciences and Pharmacy and the Priority Research Centre for Stroke and Brain Injury, The University of Newcastle, University Dr, Callaghan, NSW 2308, Australia.

Cognitive impairment is common after stroke, and disturbances in hippocampal function are often involved, even in remote non-hippocampal injuries. In terms of hippocampal function, growth hormone (GH) is known to affects plasticity and cognition. We aimed to investigate whether GH treatment after an experimental cortical stroke could enhance remote hippocampal plasticity and the hippocampal-dependent visual discrimination task. C57BL6 male mice were subjected to cortical photothrombotic stroke. Stroke mice were then treated with either saline or GH at 48 h after occlusion for 28 days. We assessed learning and memory using mouse touchscreen platform for the visual discrimination task. We also evaluated markers of neural progenitor cells, synaptic plasticity and cerebrovascular remodelling in the hippocampal formation. GH treatment significantly improved the performance on visual discrimination task after stroke. We observed a concomitant increased number of bromodeoxyuridine-positive cells in the dentate gyrus of the hippocampus. We also detected increased protein levels and density of doublecortin, a neuronal precursor cells marker, as well as glutamate receptor 1 (GLuR1), a synaptic marker. These findings provide further neurobiological evidence for how GH treatment could be used to promote hippocampal plasticity in a remote region from the initial cortical injury, and thus enhance cognitive recovery after stroke.
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http://dx.doi.org/10.3390/ijms21124563DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7349868PMC
June 2020

Disease characteristics of MCT8 deficiency: an international, retrospective, multicentre cohort study.

Lancet Diabetes Endocrinol 2020 07;8(7):594-605

Department of Diabetes and Endocrinology, Women's and Children's Hospital, North Adelaide, SA, Australia.

Background: Disordered thyroid hormone transport, due to mutations in the SLC16A2 gene encoding monocarboxylate transporter 8 (MCT8), is characterised by intellectual and motor disability resulting from cerebral hypothyroidism and chronic peripheral thyrotoxicosis. We sought to systematically assess the phenotypic characteristics and natural history of patients with MCT8 deficiency.

Methods: We did an international, multicentre, cohort study, analysing retrospective data from Jan 1, 2003, to Dec 31, 2019, from patients with MCT8 deficiency followed up in 47 hospitals in 22 countries globally. The key inclusion criterion was genetically confirmed MCT8 deficiency. There were no exclusion criteria. Our primary objective was to analyse the overall survival of patients with MCT8 deficiency and document causes of death. We also compared survival between patients who did or did not attain full head control by age 1·5 years and between patients who were or were not underweight by age 1-3 years (defined as a bodyweight-for-age Z score <-2 SDs or <5th percentile according to WHO definition). Other objectives were to assess neurocognitive function and outcomes, and clinical parameters including anthropometric characteristics, biochemical markers, and neuroimaging findings.

Findings: Between Oct 14, 2014, and Jan 17, 2020, we enrolled 151 patients with 73 different MCT8 (SLC16A2) mutations. Median age at diagnosis was 24·0 months (IQR 12·0-60·0, range 0·0-744·0). 32 (21%) of 151 patients died; the main causes of mortality in these patients were pulmonary infection (six [19%]) and sudden death (six [19%]). Median overall survival was 35·0 years (95% CI 8·3-61·7). Individuals who did not attain head control by age 1·5 years had an increased risk of death compared with patients who did attain head control (hazard ratio [HR] 3·46, 95% CI 1·76-8·34; log-rank test p=0·0041). Patients who were underweight during age 1-3 years had an increased risk for death compared with patients who were of normal bodyweight at this age (HR 4·71, 95% CI 1·26-17·58, p=0·021). The few motor and cognitive abilities of patients did not improve with age, as evidenced by the absence of significant correlations between biological age and scores on the Gross Motor Function Measure-88 and Bayley Scales of Infant Development III. Tri-iodothyronine concentrations were above the age-specific upper limit in 96 (95%) of 101 patients and free thyroxine concentrations were below the age-specific lower limit in 94 (89%) of 106 patients. 59 (71%) of 83 patients were underweight. 25 (53%) of 47 patients had elevated systolic blood pressure above the 90th percentile, 34 (76%) of 45 patients had premature atrial contractions, and 20 (31%) of 64 had resting tachycardia. The most consistent MRI finding was a global delay in myelination, which occurred in 13 (100%) of 13 patients.

Interpretation: Our description of characteristics of MCT8 deficiency in a large patient cohort reveals poor survival with a high prevalence of treatable underlying risk factors, and provides knowledge that might inform clinical management and future evaluation of therapies.

Funding: Netherlands Organisation for Health Research and Development, and the Sherman Foundation.
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http://dx.doi.org/10.1016/S2213-8587(20)30153-4DOI Listing
July 2020

Growth Hormone Promotes Motor Function after Experimental Stroke and Enhances Recovery-Promoting Mechanisms within the Peri-Infarct Area.

Int J Mol Sci 2020 Jan 17;21(2). Epub 2020 Jan 17.

School of Biomedical Sciences and Pharmacy and the Priority Research Centre for Stroke and Brain Injury, the University of Newcastle, University Dr, Callaghan, NSW 2308, Australia.

Motor impairment is the most common and widely recognised clinical outcome after stroke. Current clinical practice in stroke rehabilitation focuses mainly on physical therapy, with no pharmacological intervention approved to facilitate functional recovery. Several studies have documented positive effects of growth hormone (GH) on cognitive function after stroke, but surprisingly, the effects on motor function remain unclear. In this study, photothrombotic occlusion targeting the motor and sensory cortex was induced in adult male mice. Two days post-stroke, mice were administered with recombinant human GH or saline, continuing for 28 days, followed by evaluation of motor function. Three days after initiation of the treatment, bromodeoxyuridine was administered for subsequent assessment of cell proliferation. Known neurorestorative processes within the peri-infarct area were evaluated by histological and biochemical analyses at 30 days post-stroke. This study demonstrated that GH treatment improves motor function after stroke by 50%-60%, as assessed using the cylinder and grid walk tests. Furthermore, the observed functional improvements occurred in parallel with a reduction in brain tissue loss, as well as increased cell proliferation, neurogenesis, increased synaptic plasticity and angiogenesis within the peri-infarct area. These findings provide new evidence about the potential therapeutic effects of GH in stroke recovery.
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http://dx.doi.org/10.3390/ijms21020606DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7013985PMC
January 2020

Requirements for improving health and well-being of children with Prader-Willi syndrome and their families.

J Paediatr Child Health 2019 Sep 30;55(9):1029-1037. Epub 2019 Jun 30.

Telethon Kids Institute, Centre for Child Health Research, University of Western Australia, Perth, Western Australia, Australia.

Prader-Willi syndrome (PWS) is a rare genetic condition with multi-system involvement. The literature was reviewed to describe neurodevelopment and the behavioural phenotype, endocrine and metabolic disorders and respiratory and sleep functioning. Implications for child and family quality of life were explored. Challenging behaviours contribute to poorer well-being and quality of life for both the child and caregiver. Recent evidence indicates healthy outcomes of weight and height can be achieved with growth hormone therapy and dietary restriction and should be the current target for all individuals with PWS. Gaps in the literature included therapies to manage challenging behaviours, as well as understanding the effects of growth hormone on respiratory and sleep function. New knowledge regarding the transition of children and families from schooling and paediatric health services to employment, accommodation and adult health services is also needed. Developing a national population-based registry could address these knowledge gaps and inform advocacy for support services that improve the well-being of individuals with PWS and their families.
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http://dx.doi.org/10.1111/jpc.14546DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6852695PMC
September 2019

A personal series of 100 children operated for Cushing's disease (CD): optimizing minimally invasive diagnosis and transnasal surgery to achieve nearly 100% remission including reoperations.

J Pediatr Endocrinol Metab 2018 Sep;31(9):1023-1031

Department of Neuropathology, Pituitary Pathologist, University Hospital Eppendorf, Hamburg, Germany.

Background Transnasal surgery (TNS) is the first choice in the treatment of pediatric Cushing's disease. The question is how can high remission rates be achieved with minimally invasive investigations and TNS whilst avoiding radiotherapy or bilateral adrenalectomy in children. Methods Data from a published series 1 (n=55) of surgeon DKL will be compared with his recent series 2 (n=45) until 2009. All patients were operated by direct transnasal microsurgery. Over time, inferior petrosal sinus sampling (IPSS) was replaced by cavernous sinus sampling (CSS), restricted to unclear cases without increase of salivary cortisol in corticotropin-releasing hormone-test, difficult sellar anatomy or negative magnetic resonance imaging (MRI). Multiple direct intra-operative micro-cytology, micro-doppler and adequate visualization techniques are described. Results In series 1, IPSS was performed in 13 (24%) of whom 46% had false adenoma lateralization. All adenomas could be removed with extensive pituitary exploration. Three patients had early successful re-surgery. In series 2, with more refined MRI and endocrinology, CSS was used in only seven patients (15%) and all micro-adenomas were correctly localized. In three of four patients with persistent cortisol excess, repeat-TNS was necessary and successful. Side effects of TNS were minimal. Recurrence rates were 16% and 11% in series 1 and 2, respectively. Only four of 100 children with invasive adenomas were irradiated, significantly less than in other experienced pediatric centers. Conclusions Thus, 98% remission rate could be achieved with fewer invasive pre-surgical investigations, such as central catheter studies, refined TNS and early repeat-TNS. Repeat-TNS in recurrences minimized the need for irradiation.
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http://dx.doi.org/10.1515/jpem-2018-0262DOI Listing
September 2018

Recurrences of Pituitary Adenomas or Second De Novo Tumors: Comparisons with First Tumors.

World Neurosurg 2018 Nov 17;119:e118-e124. Epub 2018 Jul 17.

Clinic of Neurosurgery, University of Hamburg, Hamburg, Germany.

Background: Recurrences of pituitary adenomas are not so rare.

Methods: In the German Registry of Pituitary Tumors, more than 12,000 surgical specimens were collected between 1967 and 2012, of which 312 patients with altogether 334 recurrences (n = 646 specimens) were included in our study.

Results: The histopathology of 162 recurrent adenomas could be compared with the original tumor and 37 second recurrences could be compared with the first recurrence. Comparing the proliferation index (Ki-67) of the original and the first recurrent tumor (n = 162), we found an unchanged index in 43 cases (26%), whereas in 69 cases (43%) the index increased and in 50 cases (31%) it decreased. Comparing the first with the second recurrence (n = 37), we found an unchanged index in 8 cases (22%), an increased index in 15 cases (40%), and a decreased index in 14 cases (38%). The third recurrence showed an unchanged index in 1 case (20%), an increased index in 2 cases (40%), and a decreased index in 2 cases (40%). p53 was unchanged in recurrences in 44% of cases, increased in 33%, and decreased in 22%. In 4 cases, adenomas developed into adenomas with strongly increased proliferation (formerly atypical adenomas, now aggressive adenomas) for the first recurrence, and 9 recurrences became aggressive adenomas. A change of tumor type without change of the common transcription factor occurred in 82 cases.

Conclusions: A second independent de novo adenoma was present in 10 cases, probably due to changes of transcription factors.
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http://dx.doi.org/10.1016/j.wneu.2018.07.056DOI Listing
November 2018

Growth Hormone Improves Cognitive Function After Experimental Stroke.

Stroke 2018 05 10;49(5):1257-1266. Epub 2018 Apr 10.

From the Priority Research Centre for Stroke and Brain Injury (L.K.O., F.R.W., M.N., J.I.)

Background And Purpose: Cognitive impairment is a common outcome for stroke survivors. Growth hormone (GH) could represent a potential therapeutic option as this peptide hormone has been shown to improve cognition in various clinical conditions. In this study, we evaluated the effects of peripheral administration of GH at 48 hours poststroke for 28 days on cognitive function and the underlying mechanisms.

Methods: Experimental stroke was induced by photothrombotic occlusion in young adult mice. We assessed the associative memory cognitive domain using mouse touchscreen platform for paired-associate learning task. We also evaluated neural tissue loss, neurotrophic factors, and markers of neuroplasticity and cerebrovascular remodeling using biochemical and histology analyses.

Results: Our results show that GH-treated stroked mice made a significant improvement on the paired-associate learning task relative to non-GH-treated mice at the end of the study. Furthermore, we observed reduction of neural tissue loss in GH-treated stroked mice. We identified that GH treatment resulted in significantly higher levels of neurotrophic factors (IGF-1 [insulin-like growth factor-1] and VEGF [vascular endothelial growth factor]) in both the circulatory and peri-infarct regions. GH treatment in stroked mice not only promoted protein levels and density of presynaptic marker (SYN-1 [synapsin-1]) and marker of myelination (MBP [myelin basic protein]) but also increased the density and area coverage of 2 major vasculature markers (CD31 and collagen-IV), within the peri-infarct region.

Conclusions: These findings provide compelling preclinical evidence for the usage of GH as a potential therapeutic tool in the recovery phase of patients after stroke.
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http://dx.doi.org/10.1161/STROKEAHA.117.020557DOI Listing
May 2018

Young children with type 1 diabetes can achieve glycemic targets without hypoglycemia: Results of a novel intensive diabetes management program.

Pediatr Diabetes 2018 06 4;19(4):769-775. Epub 2018 Mar 4.

Department of Paediatric Endocrinology and Diabetes, John Hunter Children's Hospital, Newcastle, New South Wales, Australia.

Background: Young children with type 1 diabetes (T1D) present unique challenges for intensive diabetes management. We describe an intensive diabetes program adapted for young children and compare glycemic control, anthropometry, dietary practices and insulin regimens before and after implementation.

Methods: Cross sectional data from children with T1D aged ≥0.5 to <7.0 years attending the John Hunter Children's Hospital (JHCH), Australia in 2004, 2010 and 2016 were compared. Outcome measures were glycemic control assessed by hemoglobin A (HbA ); severe hypoglycemia episodes; body mass index standard deviation scores (BMI-SDS); diabetes ketoacidosis (DKA) episodes; and insulin regimen-twice daily injections, multiple daily injections, or continuous subcutaneous insulin infusion.

Results: Mean HbA declined by 12 mmol/mol over the study period (P < .01). The proportion of children achieving a mean HbA  < 58 mmol/mol increased significantly from 31% in 2004 to 64% in 2010 (P < .01), and from 64% in 2010 to 83% in 2016 (P = .04). The mean BMI-SDS was significantly lower in 2010 when compared with 2004 (P<.01); however, this trend plateaued between 2010 and 2016 (P = .97). Severe hypoglycemia and DKA occurred infrequently. The prevalence of overweight or obesity increased from 2010 to 2016 (P = .03).

Conclusions: The JHCH intensive diabetes management program has resulted in 83% of young children in 2016 achieving target glycemia without an increase in severe hypoglycemia or DKA. Overweight remains a challenge in this population warranting action to reduce weight and protect these children from future obesity-related health risks.
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http://dx.doi.org/10.1111/pedi.12644DOI Listing
June 2018

Molecular and clinical characterization of a series of patients with childhood-onset lysosomal acid lipase deficiency. Retrospective investigations, follow-up and detection of two novel LIPA pathogenic variants.

Atherosclerosis 2017 Oct 26;265:124-132. Epub 2017 Aug 26.

Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Italy. Electronic address:

Background And Aims: Childhood/Adult-onset Lysosomal Acid Lipase Deficiency (LAL-D) is a recessive disorder due to loss of function variants of LAL, the enzyme which hydrolyses cholesteryl esters, derived from internalized apoB containing lipoproteins. The disease is characterized by multi-organ involvement including the liver, spleen, intestine and cardiovascular system. The aim of this study was the clinical and molecular characterization of 14 (13 unrelated) previously unreported patients with childhood-onset LAL-D.

Methods: Data collected included clinical and laboratory investigations, liver imaging, liver biopsy and LIPA gene analysis. The response to lipid-lowering medications, liver transplantation and enzyme replacement therapy (ERT) was reported for some patients.

Results: LAL-D was suspected at 4.4 ± 3.3 years of age for the presence of hepatomegaly, elevated serum transaminases and hypercholesterolemia, and was confirmed by liver biopsy/imaging and LAL assay. The follow up period ranged from 3 to 40 years (mean 7.8 ± 4.0 years in 13 cases). Patients treated with statins with or without ezetimibe showed 28% reduction of plasma LDL-cholesterol without a tangible effect on liver enzymes; some patients receiving ERT showed normalized lipoprotein profile and transaminase levels. The common c.894G > A variant was observed in homozygosity or compound heterozygosity in 10 patients. We found seven previously reported variants: p.(Trp140*), p.(Arg218*), p.(Gly266*), p.(Thr288Ile), p.(Leu294Ser), p.(His295Tyr) and p.(Gly342Arg) and two novel variants: p.(Asp345Asn), affecting the LAL catalytic triad, and c.229+3A > C, affecting splicing. Homozygosity for p.(Thr288Ile) or c.229+3A > C was associated with a severe phenotype.

Conclusions: This study provides additional data on the features of childhood-onset LAL-D and describes two novel pathogenic variants of the LIPA gene.
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http://dx.doi.org/10.1016/j.atherosclerosis.2017.08.021DOI Listing
October 2017

Identification of endothelin-converting enzyme-2 as an autoantigen in autoimmune polyendocrine syndrome type 1.

Autoimmunity 2017 Jun 30;50(4):223-231. Epub 2017 May 30.

a Department of Medical Sciences , Uppsala University , Uppsala , Sweden.

Autoimmune polyendocrine syndrome type 1 (APS1) is a rare monogenic autoimmune disorder caused by mutations in the autoimmune regulator (AIRE) gene. High titer autoantibodies are a characteristic feature of APS1 and are often associated with particular disease manifestations. Pituitary deficits are reported in up to 7% of all APS1 patients, with immunoreactivity to pituitary tissue frequently reported. We aimed to isolate and identify specific pituitary autoantigens in patients with APS1. Immunoscreening of a pituitary cDNA expression library identified endothelin-converting enzyme (ECE)-2 as a potential candidate autoantigen. Immunoreactivity against ECE-2 was detected in 46% APS1 patient sera, with no immunoreactivity detectable in patients with other autoimmune disorders or healthy controls. Quantitative-PCR showed ECE-2 mRNA to be most abundantly expressed in the pancreas with high levels also in the pituitary and brain. In the pancreas ECE-2 was co-expressed with insulin or somatostatin, but not glucagon and was widely expressed in GH producing cells in the guinea pig pituitary. The correlation between immunoreactivity against ECE-2 and the major recognized clinical phenotypes of APS1 including hypopituitarism was not apparent. Our results identify ECE-2 as a specific autoantigen in APS1 with a restricted neuroendocrine distribution.
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http://dx.doi.org/10.1080/08916934.2017.1332183DOI Listing
June 2017

Low dose growth hormone treatment in infants and toddlers with Prader-Willi syndrome is comparable to higher dosage regimens.

Growth Horm IGF Res 2017 06 24;34:1-7. Epub 2017 Mar 24.

Child Health Research Centre, The University of Queensland, Brisbane, Australia.

Objective: Evaluate benefit and risk of low dose growth hormone treatment (GHT, 4.5mg/m/week) in very young children with Prader-Willi Syndrome (PWS).

Design: Prospective longitudinal clinical intervention.

Methods: We evaluated 31 infants (aged 2-12months) and 42 toddlers (13-24months) from the PWS-OZGROW database for height, weight and BMI using the World Health Organization standard deviation scores (SDS) and PWS specific BMI (SDS), bone age, insulin-like growth factor 1 (IGF-I) levels and adverse events over 3years of GHT.

Results: At commencement of GHT infants had a lower BMI SDS (-0.88 vs 0.40) than toddlers, while toddlers had a lower height SDS (-1.44 vs -2.09) (both P<0.05). All increased height SDS (2year delta height infants +1.26 SDS, toddlers+1.21 SDS), but infants normalised height sooner, achieving a height SDS of -0.56 within 1year, while toddlers achieved a height SDS of -0.88 in two years. BMI SDS increased, while BMI SDS decreased (both P<0.0001) and remained negative. The GHT response did not differ with gestation (preterm 23%) or genetic subtype (deletion vs maternal uniparental disomy). Bone age advancement paralleled chronological age. All children had low serum IGF-I at baseline which increased, but remained within the age-based reference range during GHT (for 81% in first year). Four children had spinal curvature at baseline; two improved, two progressed to a brace and two developed an abnormal curve over the observation period. Mild to severe central and/or obstructive sleep apnoea were observed in 40% of children prior to GHT initiation; 11% commenced GHT on positive airway pressure (PAP), oxygen or both. Eight children ceased GHT due to onset or worsening of sleep apnoea: 2 infants in the first few months and 6 children after 6-24months. Seven resumed GHT usually after adjusting PAP but five had adenotonsillectomy. One child ceased GHT temporarily due to respiratory illness. No other adverse events were reported. Two children substantially improved their breathing shortly after GHT initiation.

Conclusion: Initiation of GHT in infants with 4.5mg/m/week was beneficial and comparable in terms of auxological response to a dose of 7mg/m/week. Regular monitoring pre and post GH initiation assisted in early detection of adverse events. IGF-I levels increased with the lower dose but not excessively, which may lower potential long-term risks.
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http://dx.doi.org/10.1016/j.ghir.2017.03.001DOI Listing
June 2017

Disorders of sex development: insights from targeted gene sequencing of a large international patient cohort.

Genome Biol 2016 11 29;17(1):243. Epub 2016 Nov 29.

Department of Medical Genetics, Sydney Children's Hospital, Randwick, NSW, Australia.

Background: Disorders of sex development (DSD) are congenital conditions in which chromosomal, gonadal, or phenotypic sex is atypical. Clinical management of DSD is often difficult and currently only 13% of patients receive an accurate clinical genetic diagnosis. To address this we have developed a massively parallel sequencing targeted DSD gene panel which allows us to sequence all 64 known diagnostic DSD genes and candidate genes simultaneously.

Results: We analyzed DNA from the largest reported international cohort of patients with DSD (278 patients with 46,XY DSD and 48 with 46,XX DSD). Our targeted gene panel compares favorably with other sequencing platforms. We found a total of 28 diagnostic genes that are implicated in DSD, highlighting the genetic spectrum of this disorder. Sequencing revealed 93 previously unreported DSD gene variants. Overall, we identified a likely genetic diagnosis in 43% of patients with 46,XY DSD. In patients with 46,XY disorders of androgen synthesis and action the genetic diagnosis rate reached 60%. Surprisingly, little difference in diagnostic rate was observed between singletons and trios. In many cases our findings are informative as to the likely cause of the DSD, which will facilitate clinical management.

Conclusions: Our massively parallel sequencing targeted DSD gene panel represents an economical means of improving the genetic diagnostic capability for patients affected by DSD. Implementation of this panel in a large cohort of patients has expanded our understanding of the underlying genetic etiology of DSD. The inclusion of research candidate genes also provides an invaluable resource for future identification of novel genes.
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http://dx.doi.org/10.1186/s13059-016-1105-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5126855PMC
November 2016

Sotos syndrome: An unusual presentation with intrauterine growth restriction, generalized lymphedema, and intention tremor.

Am J Med Genet A 2016 Apr 6;170A(4):1064-9. Epub 2016 Jan 6.

University of Newcastle, Callaghan, New South Wales, Australia.

Sotos syndrome is a childhood overgrowth syndrome characterized clinically by a distinctive facial gestalt, advanced bone age, childhood overgrowth, and non-progressive developmental delay; and genetically by haploinsufficiency of the Nuclear receptor binding SET Domain 1 (NSD1) gene. Generalized lymphedema has not previously been associated with Sotos syndrome. Generalized lymphedema has been associated with mutations in several genes including FLT4. This gene is involved in the regulation of VEGFR3, a key governor of lymphatic-endothelial cell development and function. We report on a 28-year-old Caucasian female with a de novo NSD1 intragenic mutation, c.5841_5848dup: p.Leu1950Serfs*22, who presented with characteristic clinical features of Sotos syndrome. Unusually this case includes atypical features of intrauterine growth retardation and post-pubertal onset of primary lymphedema. To our knowledge, no link between Sotos syndrome and generalized lymphedema has previously been described in the literature. We propose a mechanism by which disruptions in NSD1 gene may lead to generalized lymphedema. Aberrations of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK)-signaling pathway has been identified in both Sotos syndrome and lymphedema. This finding extends the known phenotype of Sotos syndrome through the inclusion of lymphedema. This case also indicates that presence of low birth weight does not exclude the possibility of Sotos syndrome.
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http://dx.doi.org/10.1002/ajmg.a.37535DOI Listing
April 2016

Evaluation of a novel continuous glucose monitoring guided system for adjustment of insulin dosing - PumpTune: a randomized controlled trial.

Pediatr Diabetes 2016 11 24;17(7):478-482. Epub 2015 Dec 24.

Department of Paediatric Endocrinology and Diabetes, John Hunter Children's Hospital, Newcastle, New South Wales, Australia.

Objective: Retrospective continuous glucose monitoring (CGM) can guide insulin pump adjustments, however, interpretation of data and recommending new pump settings is complex and subjective. We aimed to compare the safety and glycaemic profiles of children after their diabetologist or a novel algorithm (PumpTune) adjusted their insulin pump settings.

Research Design And Methods: In a randomized cross-over trial of 22 patients aged 6-14 yr with type 1 diabetes with mean Hba1c 7.4% (57 mmol/mol) using CSII, CGM was used over two periods each of 6.5 d to assess percentage time glucose remained within, above and below 3.9-10.0 mmol/L. Before the start of one period pump settings were adjusted by the patient's diabetologist, and before the other insulin pump settings were adjusted by PumpTune.

Results: A total of 63.4% of the sensor glucose levels were within target range with PumpTune settings and 57.4% were within range with the clinician settings (p = 0.016). The time spent above target range with PumpTune was 26.9% and with clinician settings was 33.5% (p = 0.021). The time spent below target range with PumpTune was 9.7% and with clinician settings was 9.2% (p = 0.77). The mean number of times when a sensor glucose level <2.75 mmol/L was recorded with PumpTune settings was 2.9 compared with 3.7 with clinician settings (p = 0.39). There were no serious adverse outcomes and no difference in parent-assessed satisfaction.

Conclusions: Automated insulin pump adjustment with PumpTune is feasible and warrants testing in a larger more varied population over a longer time. In this well-controlled group of children, PumpTune achieved a more favorable glucose profile.
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http://dx.doi.org/10.1111/pedi.12332DOI Listing
November 2016

Spontaneous and tetracosactide-induced anti-ACTH antibodies in man.

Clin Endocrinol (Oxf) 2016 Apr 25;84(4):489-95. Epub 2015 Jun 25.

Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.

Context: During a clinical trial of regular tetracosactide depot injections, four of 13 patients with autoimmune Addison's disease (AAD) developed adverse reactions immediately following tetracosactide injections. We wished to investigate whether these adverse effects could be due to the production of circulating antitetracosactide (ACTH1-24 ) antibodies.

Design: Anti-ACTH binding activity was investigated using immunoblotting and ELISA on sera from participants in the trial (n = 13; baseline and after tetracosactide exposure), 131 unrelated patients with AAD, 92 patients with Graves' disease (GD), 15 patients with isolated ACTH deficiency and 102 controls. Immunohistochemistry of human pituitary tissue sections was also performed using pooled sera.

Results: Bands at approximately 4 and 6 kDa, corresponding to ACTH1-24 and full-length ACTH1-39, respectively, were found in 10 of 13 (77%) of sera from trial patients exposed to tetracosactide, including all those who had an adverse reaction. This is in contrast with healthy control sera, which showed no binding. The same 10 subjects also showed high levels of binding to tetracosactide by ELISA, along with 21% of patients with AAD, 14% of patients with GD (both P < 0·001 compared to controls) and 1 isolated ACTH deficiency patient (7% of 15). These sera also recognized native ACTH in human pituitary sections.

Conclusion: Our study demonstrates that repeated administration of depot tetracosactide can lead to anti-ACTH1-24 autoreactivity. In addition, a significant number of patients with AAD and GD also had similar, spontaneous, anti-ACTH reactivity. The presence of these antibodies could mediate some of the adverse effects or explain the well-described phenomenon of resistance to chronic ACTH therapy.
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http://dx.doi.org/10.1111/cen.12795DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4949547PMC
April 2016

A novel X-linked trichothiodystrophy associated with a nonsense mutation in RNF113A.

J Med Genet 2015 Apr 22;52(4):269-74. Epub 2015 Jan 22.

Genetics of Learning Disability Service, Hunter Genetics, Waratah, Australia.

Background: Trichothiodystrophy (TTD) is a group of rare autosomal recessive disorders that variably affect a wide range of organs derived from the neuroectoderm. The key diagnostic feature is sparse, brittle, sulfur deficient hair that has a 'tiger-tail' banding pattern under polarising light microscopy.

Patients And Methods: We describe two male cousins affected by TTD associated with microcephaly, profound intellectual disability, sparse brittle hair, aged appearance, short stature, facial dysmorphism, seizures, an immunoglobulin deficiency, multiple endocrine abnormalities, cerebellar hypoplasia and partial absence of the corpus callosum, in the absence of cellular photosensitivity and ichthyosis. Obligate female carriers showed 100% skewed X-chromosome inactivation. Linkage analysis and Sanger sequencing of 737 X-chromosome exons and whole exome sequencing was used to find the responsible gene and mutation.

Results: Linkage analysis localised the disease allele to a 7.75 Mb interval from Xq23-q25. We identified a nonsense mutation in the highly conserved RNF113A gene (c.901 C>T, p.Q301*). The mutation segregated with the disease in the family and was not observed in over 100,000 control X chromosomes. The mutation markedly reduced RNF113A protein expression in extracts from lymphoblastoid cell lines derived from the affected individuals.

Conclusions: The association of RNF113A mutation with non-photosensitive TTD identifies a new locus for these disorders on the X chromosome. The extended phenotype within this family includes panhypopituitarism, cutis marmorata and congenital short oesophagus.
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http://dx.doi.org/10.1136/jmedgenet-2014-102418DOI Listing
April 2015

A rare case of pituitary infarction leading to spontaneous tumour resolution and CSF-sella syndrome in an 11-year-old girl and a review of the paediatric literature.

J Pediatr Endocrinol Metab 2014 Sep;27(9-10):939-46

Pituitary infarction or apoplexy with spontaneous cure of the underlying pituitary adenoma is rare. In the paediatric population, we found only a few reported cases. We report a rare case of pituitary infarction progressing to CSF-sella syndrome (or empty sella) in an 11-year-old girl. She presented with sudden onset vomiting, moderate headaches, lethargy, weight loss, and tall stature above her mid-parental height. She did not have any severe symptoms of apoplexy. Her clinical and radiological findings suggested infarction of a pituitary lesion, such as a pituitary adenoma or infarction of a cystic lesion, such as a Rathke's cleft cyst. In this report, we discuss her case of probable infarction of a growth hormone secreting adenoma with a phase of accelerated growth ending up with total anterior pituitary insufficiency. The differential diagnosis and review of the rare cases of paediatric pituitary infarction in the literature will be discussed.
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http://dx.doi.org/10.1515/jpem-2014-0143DOI Listing
September 2014

Comprehensive genotyping and clinical characterisation reveal 27 novel NKX2-1 mutations and expand the phenotypic spectrum.

J Med Genet 2014 Jun 8;51(6):375-87. Epub 2014 Apr 8.

Institute for Experimental Pediatric Endocrinology, Charité University Medicine, Berlin, Germany.

Background: NKX2-1 encodes a transcription factor with large impact on the development of brain, lung and thyroid. Germline mutations of NKX2-1 can lead to dysfunction and malformations of these organs. Starting from the largest coherent collection of patients with a suspected phenotype to date, we systematically evaluated frequency, quality and spectrum of phenotypic consequences of NKX2-1 mutations.

Methods: After identifying mutations by Sanger sequencing and array CGH, we comprehensively reanalysed the phenotype of affected patients and their relatives. We employed electrophoretic mobility shift assay (EMSA) to detect alterations of NKX2-1 DNA binding. Gene expression was monitored by means of in situ hybridisation and compared with the expression level of MBIP, a candidate gene presumably involved in the disorders and closely located in close genomic proximity to NKX2-1.

Results: Within 101 index patients, we detected 17 point mutations and 10 deletions. Neurological symptoms were the most consistent finding (100%), followed by lung affection (78%) and thyroidal dysfunction (75%). Novel symptoms associated with NKX2-1 mutations comprise abnormal height, bouts of fever and cardiac septum defects. In contrast to previous reports, our data suggest that missense mutations in the homeodomain of NKX2-1 not necessarily modify its DNA binding capacity and that this specific type of mutations may be associated with mild pulmonary phenotypes such as asthma. Two deletions did not include NKX2-1, but MBIP, whose expression spatially and temporarily coincides with NKX2-1 in early murine development.

Conclusions: The high incidence of NKX2-1 mutations strongly recommends the routine screen for mutations in patients with corresponding symptoms. However, this analysis should not be confined to the exonic sequence alone, but should take advantage of affordable NGS technology to expand the target to adjacent regulatory sequences and the NKX2-1 interactome in order to maximise the yield of this diagnostic effort.
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http://dx.doi.org/10.1136/jmedgenet-2013-102248DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5240655PMC
June 2014

Population-based incidence of diabetes in Australian youth aged 10-18 yr: increase in type 1 diabetes but not type 2 diabetes.

Pediatr Diabetes 2014 Dec 17;15(8):585-90. Epub 2014 Mar 17.

Institute of Endocrinology and Diabetes, The Children's Hospital at Westmead, Westmead, Australia; School of Women's and Children's Health, University of New South Wales, Sydney, Australia.

Background: Global incidence of childhood type 2 diabetes has increased, with a greater rise amongst certain ethnic groups.

Objectives: To examine the change in the incidence of type 1 and type 2 diabetes in Australian youth, aged 10-18 yr, in New South Wales, Australia.

Methods: Prospective population-based incidence study (2001-2008). Primary case ascertainment was from the Australasian Paediatric Endocrine Group Diabetes Register, secondary independent ascertainment from the National Diabetes Register.

Results: There were 202 incident cases of type 2 diabetes (96 boys, 48%). The mean age at diagnosis (±SD) was 14.6 ± 2.5 yr; 93% were overweight (International Obesity Taskforce Grade ≥1). Mean HbA1c was 8.8 ± 2.8%. Ethnicity was Caucasian 31%, Indigenous Australian 20%, Southeast Asian 11%, North African/Middle Eastern 9%, and NewZealander/Melanesian/Polynesian 8%. The mean annual incidence of type 2 diabetes was 3.0 per 100 000 per year (95% confidence interval (CI): 2.6-3.4) and did not change over time. The mean annual incidence of type 1 diabetes was 22.0 per 100 000 per year (95% CI: 20.8-23.1), and increased by 3.8% per year [incidence rate ratio IRR: 1.04, 95% CI: 1.02-1.06, p = 0.001]. Incidence was higher in Indigenous vs. non-Indigenous youth, IRR: 6.9 (95% CI: 4.7-10.2, p < 0.001).

Conclusion: In 10-18 yr old youth, in Australia, the incidence of type 2 diabetes has remained steady during the last decade; however, the incidence of type 1 diabetes continues to rise. Most common diabetes in Australian youth is type 1 diabetes.
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http://dx.doi.org/10.1111/pedi.12131DOI Listing
December 2014

Non-invasive detection of microvascular changes in a paediatric and adolescent population with type 1 diabetes: a pilot cross-sectional study.

BMC Endocr Disord 2013 Oct 5;13:41. Epub 2013 Oct 5.

John Hunter Children's Hospital, New Lambton, NSW 2305, Australia.

Background: The detection of microvascular damage in type 1 diabetes is difficult and traditional investigations do not detect changes until they are well established. The purpose of this study was to investigate the combined ability of nailfold capillaroscopy, laser Doppler flowmetry, retinal vessel analysis and 24-hr ambulatory blood pressure monitoring to detect early microvascular changes in a paediatric and adolescent population with type 1 diabetes.

Methods: Patients aged between 8 - 18 years with type I diabetes and no other autoimmune conditions were studied. The participants underwent the above cardiac and vascular investigations in a single three-hour session. Standard parameters including HbA1c were also investigated. Associations between all parameters were described by correlation analysis. Fisher's exact and t-tests determined the association with clinical findings.

Results: 26 participants were recruited. The mean HbA1c was 8.1% (SD ± 1.1) with a mean duration of type 1 diabetes of 7.9 years (SD ± 3.4). Three participants had microalbuminuria and one had early signs of retinopathy. Participants with microvascular complications had more avascular areas on nailfold capillaroscopy (p = 0.03). Recent HbA1c was positively associated with the number of nailfold microhaemorrhages (p = 0.03) Decreased baseline perfusion by laser Doppler flowmetry was associated with increased capillary density (p = 0.001) and an increased number of microaneurysms (p = 0.04) on nailfold capillaroscopy.

Conclusions: This pilot study has shown that in children and adolescents with established type 1 diabetes, abnormal microvasculature can be detected by these investigations. These markers were also positively associated with evidence of suboptimal diabetes control as assessed by HbA1c. Further research will be necessary to determine the practical role of these investigations in the management and progress of the complications of type 1 diabetes.

Trial Registration: Clinical Trial number NCT01279928, ClinicalTrials.gov.
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http://dx.doi.org/10.1186/1472-6823-13-41DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3852758PMC
October 2013

Response to growth hormone treatment in Prader-Willi syndrome: auxological criteria versus genetic diagnosis.

J Paediatr Child Health 2013 Dec 19;49(12):1045-51. Epub 2013 Jun 19.

School of Medicine, The University of Queensland, Brisbane, Australia; Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Australia.

Aim: The Australian Prader-Willi Syndrome (PWS) database was established to monitor the efficacy and safety of growth hormone (GH) treatment in PWS. This study aims to compare response to GH based on eligibility criteria.

Methods: Comparative study: 72 children received GH on the basis of short stature or evidence of GH deficiency (pre-2009: PWS-SS) and 94 on a genetic diagnosis (post-2009: PWS-Dx). We report on mandatory patient data for GH prescription: median and standard deviation score (SDS) for height and body mass index (BMI), waist/height ratio, bone age/chronological age ratio and adverse events. Comparisons were made using non-parametric tests.

Results: At baseline, the PWS-SS cohort was shorter (height SDS: -2.6 vs. -1.1, P < 0.001), had a lower BMI (0.6 vs. 1.5 SDS, P < 0.05) and greater bone age delay (bone age/chronological age: 0.7 vs. 0.9, P < 0.05) than the PWS-Dx cohort. PWS-SS parents were shorter (mid-parental height SDS: -0.13 vs. 0.28, P < 0.005). Mean change in height over 2 years was 0.9 SDS and in BMI using PWS reference standards -0.3 SDSPWS (n = 106) (year 2, height SDS: PWS-SS = -1.7, PWS-Dx = 0.1; BMI SDSPWS : PWS-SS = -1.0, PWS-Dx = -0.6). The waist/height ratio reduced (PWS-Dx: 0.60 vs. 0.56, P < 0.05) and bone age delay was unchanged over this period. No serious adverse events were reported.

Conclusions: The PWS-SS cohort represents a subgroup of the wider PWS-Dx population; however both cohorts improved height SDS with normalisation of height in the PWS-Dx cohort and lowering of BMI relative to PWS standards supporting the efficacy of treatment under the current Australian GH programme.
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http://dx.doi.org/10.1111/jpc.12294DOI Listing
December 2013

Intermediate lobe immunoreactivity in a patient with suspected lymphocytic hypophysitis.

Pituitary 2014 Feb;17(1):22-9

Department of Paediatric Endocrinology and Diabetes, John Hunter Children's Hospital, New Lambton Heights, NSW, Australia.

Lymphocytic hypophysitis is an organ-specific autoimmune disease characterised by destruction of pituitary hormone-secreting cells due to attack by self-reactive T lymphocytes. The spectrum of pituitary autoantibodies characterised by indirect immunofluorescence (IF) in these patients has not been substantially defined. The purpose of this study was to determine the spectrum of pituitary autoantibodies in 16 lymphocytic hypophysitis patients. Pituitary sections were prepared from guinea pigs and sera from 16 lymphocytic hypophysitis patients (13 biopsy proven and 3 suspected cases) and 13 healthy controls were evaluated for immunoreactivity to the pituitary tissue by immunofluorescence. A single patient was found to have high titre pituitary autoantibodies against guinea pig pituitary tissue. Immunoreactivity was directed against cells of the intermediate lobe. We present the case report of the patient who is a 24 year old woman that presented with headaches, polyuria and polydipsia. A uniformly enlarged pituitary mass was visible on MRI and a diagnosis of suspected lymphocytic hypophysitis was made. Based on our IF study, we postulate this patient has an autoimmune process directed towards the major cell type in the intermediate lobe, the melanotroph. Pre-adsorption with peptides representing adrenocorticotropic hormone, α-melanocyte stimulating hormone or β-endorphin did not affect the IF signal suggesting our patient's pituitary autoantibodies may target some other product of Proopiomelanocortin (POMC) processing, such as corticotrophin-like intermediate peptide or γ-lipoprotein. Alternatively, the autoantibodies may target a peptide completely unrelated to POMC processing.
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http://dx.doi.org/10.1007/s11102-013-0461-9DOI Listing
February 2014

Identification of TPIT and other novel autoantigens in lymphocytic hypophysitis: immunoscreening of a pituitary cDNA library and development of immunoprecipitation assays.

Eur J Endocrinol 2012 Mar 22;166(3):391-8. Epub 2011 Dec 22.

Department of Paediatric Endocrinology and Diabetes, Faculty of Health, Locked Bag 1, Newcastle Mail Centre, John Hunter Children's Hospital, University of Newcastle, Newcastle 2310, New South Wales, Australia.

Background: Lymphocytic hypophysitis is an organ-specific autoimmune disease of the pituitary gland. A specific and sensitive serological test currently does not exist to aid in the diagnosis.

Objective: To identify target autoantigens in lymphocytic hypophysitis and develop a diagnostic assay for these proteins.

Design/methods: A pituitary cDNA expression library was immunoscreened using sera from four patients with lymphocytic hypophysitis. Relevant cDNA clones from screening, along with previously identified autoantigens pituitary gland-specific factor 1a and 2 (PGSF1a and PGSF2) and neuron-specific enolase (NSE) were tested in an in vitro transcription and translation immunoprecipitation assay. The corticotroph-specific transcription factor, TPIT, was investigated separately as a candidate autoantigen.

Results: Significantly positive autoantibody reactivity against TPIT was found in 9/86 hypophysitis patients vs 1/90 controls (P = 0.018). The reactivity against TPIT was not specific for lymphocytic hypophysitis with autoantibodies detectable in the sera from patients with other autoimmune endocrine diseases. Autoantibodies were also detected against chromodomain-helicase-DNA binding protein 8, presynaptic cytomatrix protein (piccolo), Ca(2+)-dependent secretion activator, PGSF2 and NSE in serum samples from patients with lymphocytic hypophysitis, but at a frequency that did not differ from healthy controls. Importantly, 8/86 patients with lymphocytic hypophysitis had autoantibodies against any two autoantigens in comparison with 0/90 controls (P = 0.0093).

Conclusions: TPIT, a corticotroph-specific transcription factor, was identified as a target autoantigen in 10.5% of patients with lymphocytic hypophysitis. Further autoantigens related to vesicle processing were also identified as potential autoantigens with different immunoreactivity patterns in patients and controls.
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http://dx.doi.org/10.1530/EJE-11-1015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3290121PMC
March 2012

Changes in altitude cause unintended insulin delivery from insulin pumps: mechanisms and implications.

Diabetes Care 2011 Sep 4;34(9):1932-3. Epub 2011 Aug 4.

University of Newcastle,Newcastle, New South Wales, Australia.

Objective: Children and adults with type 1 diabetes who receive insulin pump therapy have reported hypoglycemia during air travel. We studied the effects of atmospheric pressure on insulin pump delivery.

Research Design And Methods: Ten insulin pumps were connected to capillary tubes. The effects of changes in ambient pressure on insulin delivery, bubble formation, bubble size, and cartridge plunger movement were analyzed.

Results: During a flight (200 mmHg pressure decrease), excess insulin delivery of 0.623% of the cartridge volume occurred (P < 0.001, Student t test). In hypobaric chamber studies, bubbles developed in the insulin when the pressure decreased and displaced the insulin out of the cartridge. Pre-existing bubbles changed in size consistent with Boyle law. Cartridge plunger movement did not occur in normal flight conditions but did occur when catastrophic plane depressurization was mimicked.

Conclusions: Atmospheric pressure reduction causes predictable, unintended insulin delivery in pumps by bubble formation and expansion of existing bubbles.
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http://dx.doi.org/10.2337/dc11-0139DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3161261PMC
September 2011

Increased detection of cystic-fibrosis-related diabetes in Australia.

Arch Dis Child 2011 Sep 8;96(9):823-6. Epub 2011 Jun 8.

Institute of Endocrinology and Diabetes, Children's Hospital at Westmead, Locked Bag 4001, Westmead, 2145 NSW, Australia

Objectives: To estimate the incidence of cystic-fibrosis-related diabetes (CFRD) in youth from New South Wales (NSW) and the Australian Capital Territory (ACT), Australia and to examine demographic/clinical features at diagnosis.

Methods: Incident cases of CFRD in young people aged ≤ 18 years diagnosed during 2000 to 2008 were identified from four paediatric cystic fibrosis (CF) clinics and the NSW/ACT Australasian Paediatric Endocrine Group Diabetes Register.

Results: CFRD was diagnosed in 41 cases (59% girls). The estimated mean annual incidence of CFRD among patients with CF was 9.4 per 1000 person years (95% CI 6.8 to 12.8). Incidence increased from 2.0 per 1000 person years in 2000 to 22.1 per 1000 in 2008 (incidence RR 1.3, 95% CI 1.1 to 1.4). Haemoglobin A1c (HbA1c) was abnormal in the majority at diagnosis: median HbA1c was 6.9% (6.2-8.1%). More cases were diagnosed using an oral glucose tolerance test in 2007-2008 compared with previous years (61% vs 6%, p<0.001).

Conclusions: CFRD is increasingly recognised and now affects approximately one in five young people with CF. The rising incidence is likely to be due to increased detection, resulting from greater awareness and changes in screening practices. Widespread uptake of consensus guidelines for screening will ensure accurate case detection, but will also impact on patient care and resource allocation.
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http://dx.doi.org/10.1136/adc.2010.208652DOI Listing
September 2011

Normal cortisol response on low-dose synacthen (1 microg) test in children with Prader Willi syndrome.

J Clin Endocrinol Metab 2010 Dec 1;95(12):E464-7. Epub 2010 Sep 1.

Department of Pediatric Endocrinology, Mater Children's Hospital, South Brisbane, Queensland 4101, Australia.

Introduction: It has been postulated that central adrenal insufficiency (CAI), resulting from hypothalamic dysfunction, may contribute to the increased unexplained death rates in Prader Willi syndrome (PWS). A study using the overnight metyrapone test reported a 60% prevalence of CAI in children with PWS. We used a low-dose Synacthen test to screen for CAI in children with PWS.

Methods: We studied 41 children with genetic diagnosis of PWS [20 males; mean age, 7.68 (±5.23) yr] in five pediatric endocrinology centers in Australasia. All participants were randomly selected, and none had a history of Addisonian crisis. Ten of the cohort were receiving sex hormone therapy, 19 were receiving GH, and four were receiving T4. Their mean body mass index z-score was +1.48 (±1.68). Baseline morning ACTH and cortisol levels were measured, followed by iv administration of 1 μg Synacthen. Post-Synacthen cortisol levels were measured at 30 min, and a cortisol level above 500 nmol/liter was considered normal.

Results: The mean baseline ACTH and cortisol were 15 (±14) ng/liter and 223 (±116) nmol/liter, respectively. The mean 30-min plasma cortisol was 690 (±114) nmol/liter, and the average increase from baseline was 201%.

Conclusions: Our result suggests that CAI is rare in children with PWS.
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http://dx.doi.org/10.1210/jc.2010-0647DOI Listing
December 2010

Clinical, genetic, and enzymatic characterization of P450 oxidoreductase deficiency in four patients.

J Clin Endocrinol Metab 2009 Dec 16;94(12):4992-5000. Epub 2009 Oct 16.

Department of Pediatrics, University of California San Francisco, San Francisco, California 94143, USA.

Context: P450 oxidoreductase (POR) deficiency causes disordered steroidogenesis; severe mutations cause genital ambiguity in both sexes plus the Antley-Bixler skeletal malformation syndrome, whereas mild mutations can cause adult infertility.

Objective: We describe four patients with POR deficiency and identify and characterize the activities of their mutations. A 46,XY male with micropenis and two 46,XX female infants with genital ambiguity presented with skeletal malformations, and a 46,XX adolescent presented with primary amenorrhea, elevated 17alpha-hydroxyprogesterone, and low sex steroids.

Methods: The coding regions of the POR gene were sequenced, and the identified mutations were recreated in human POR cDNA expression vectors lacking 27 N-terminal residues. POR and human P450c17 were expressed in bacteria. POR activity was measured by four assays: reduction of cytochrome c, oxidation of reduced nicotinamide adenine dinucleotide phosphate, and support of the 17alpha-hydroxylase and 17,20 lyase activities of P450c17.

Results: All four patients were compound heterozygotes for POR mutations, including five novel mutations: L577R, N185K, delE217, and frameshift mutations 1363delC and 697-698insGAAC. N185K and delE217 lacked measurable activity in the assays based on P450c17 but retained partial activity in the assays based on cytochrome c. As assessed by V(max)/Km, L577R supported 46% of 17alpha-hydroxylase activity but only 27% of 17,20 lyase activity. Computational modeling of these novel mutants revealed the structural basis for their reduced or absent activities.

Conclusion: These patients illustrate the broad clinical spectrum of POR deficiency, including amenorrhea and infertility as the sole manifestation. POR assays based on P450c17 correlate well with hormonal and clinical phenotypes.
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http://dx.doi.org/10.1210/jc.2009-1460DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2795645PMC
December 2009

The A, B, C, D of hypercalcaemia in Down syndrome.

BMJ Case Rep 2009 5;2009. Epub 2009 Mar 5.

Hunter Area Pathology Service, Clinical Chemistry, Locked Bag 1, HRMC, Newcastle, New South Wales, 2310, Australia.

Hypercalcaemia in infants with Down syndrome is an uncommon condition with only five previous case reports. The patients often present in the toddler years with the classical triad of Down syndrome, biochemical hypercalcaemia, and nephrocalcinosis. We present the sixth case and second male with this condition and further review the clinical details of this under-recognised condition and stratify the diagnostic criteria. The management mandates a reduction in calcium intake as a first step. The natural history of the various aspects of this condition is also considered.
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http://dx.doi.org/10.1136/bcr.06.2008.0232DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3030300PMC
November 2011

The addition of rosiglitazone to insulin in adolescents with type 1 diabetes and poor glycaemic control: a randomized-controlled trial.

Pediatr Diabetes 2008 Jul 7;9(4 Pt 1):326-34. Epub 2008 May 7.

Department of Endocrinology, Sydney Children's Hospital, Randwick, New South Wales, Australia.

Objective: To evaluate the effect of rosiglitazone, an insulin sensitizer, on glycaemic control and insulin resistance in adolescents with type 1 diabetes mellitus (T1DM) RESEARCH DESIGN AND METHODS: Randomized, double-blind, placebo-controlled crossover trial of rosiglitazone (4 mg twice daily) vs. placebo (24 wk each, with a 4 wk washout period). Entry criteria were diabetes duration >1 yr, age 10-18 yr, puberty (>or=Tanner breast stage 2 or testicular volume >4 mL), insulin dose >or=1.1 units/kg/day, and haemoglobin A1c (HbA1c) >8%. Responses to rosiglitazone were compared with placebo using paired t-tests.

Results: Of 36 adolescents recruited (17 males), 28 completed the trial. At baseline, age was 13.6 +/- 1.8 yr, HbA1c 8.9 +/- 0.96%, body mass index standard deviation scores (BMI-SDS) 0.94 +/- 0.74 and insulin dose 1.5 +/- 0.3 units/kg/day. Compared with placebo, rosiglitazone resulted in decreased insulin dose (5.8% decrease vs. 9.4% increase, p = 0.02), increased serum adiponectin (84.8% increase vs. 26.0% decrease, p < 0.01), increased cholesterol (+0.5 mmol/L vs. no change, p = 0.02), but no significant change in HbA1c (-0.3 vs. -0.1, p = 0.57) or BMI-SDS (0.08 vs. 0.04, p = 0.31). Insulin sensitivity was highly variable in the seven subjects who consented to euglycaemic hyperinsulinaemic clamps. There were no major adverse effects attributable to rosiglitazone.

Conclusion: The addition of rosiglitazone to insulin did not improve HbA1c in this group of normal weight adolescents with T1DM.
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http://dx.doi.org/10.1111/j.1399-5448.2008.00383.xDOI Listing
July 2008
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