Publications by authors named "Vernon R Sutton"

17 Publications

  • Page 1 of 1

Person Ability Scores as an Alternative to Norm-Referenced Scores as Outcome Measures in Studies of Neurodevelopmental Disorders.

Am J Intellect Dev Disabil 2020 11;125(6):475-480

Judith S. Miller, University of Pennsylvania.

Although norm-referenced scores are essential to the identification of disability, they possess several features which affect their sensitivity to change. Norm-referenced scores often decrease over time among people with neurodevelopmental disorders who exhibit slower-than-average increases in ability. Further, the reliability of norm-referenced scores is lower at the tails of the distribution, resulting in floor effects and increased measurement error for people with neurodevelopmental disorders. In contrast, the person ability scores generated during the process of constructing a standardized test with item response theory are designed to assess change. We illustrate these limitations of norm-referenced scores, and relative advantages of ability scores, using data from studies of autism spectrum disorder and creatine transporter deficiency.
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http://dx.doi.org/10.1352/1944-7558-125.6.475DOI Listing
November 2020

Hearing loss in individuals with osteogenesis imperfecta in North America: Results from a multicenter study.

Am J Med Genet A 2020 04 26;182(4):697-704. Epub 2019 Dec 26.

Department of Pediatric Orthopedic Surgery, Hospital for Special Surgery, New York, New York.

Hearing loss (HL) is an extra-skeletal manifestation of the connective tissue disorder osteogenesis imperfecta (OI). Systematic evaluation of the prevalence and characteristics of HL in COL1A1/COL1A2-related OI will contribute to a better clinical management of individuals with OI. We collected and analyzed pure-tone audiometry data from 312 individuals with OI who were enrolled in the Linked Clinical Research Centers and the Brittle Bone Disorders Consortium. The prevalence, type, and severity of HL in COL1A1/COL1A2-related OI are reported. We show that the prevalence of HL in OI is 28% and increased with age in Type I OI but not in Types III and IV. Individuals with OI Types III and IV are at a higher risk to develop HL in the first decade of life when compared to OI Type I. We also show that the prevalence of SNHL is higher in females with OI compared to males. This study reveals new insights regarding prevalence of HL in OI including a lower general prevalence of HL in COL1A1/COL1A2-related OI than previously reported (28.3 vs. 65%) and high prevalence of SNHL in females. Our data support the need in early routine hearing evaluation in all types of OI that can be adjusted to the severity of the skeletal disease.
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http://dx.doi.org/10.1002/ajmg.a.61464DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7385724PMC
April 2020

Enabling Global Clinical Collaborations on Identifiable Patient Data: The Minerva Initiative.

Front Genet 2019 29;10:611. Epub 2019 Jul 29.

Clinical Genetics Group, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford, United Kingdom.

The clinical utility of computational phenotyping for both genetic and rare diseases is increasingly appreciated; however, its true potential is yet to be fully realized. Alongside the growing clinical and research availability of sequencing technologies, precise deep and scalable phenotyping is required to serve unmet need in genetic and rare diseases. To improve the lives of individuals affected with rare diseases through deep phenotyping, global big data interrogation is necessary to aid our understanding of disease biology, assist diagnosis, and develop targeted treatment strategies. This includes the application of cutting-edge machine learning methods to image data. As with most digital tools employed in health care, there are ethical and data governance challenges associated with using identifiable personal image data. There are also risks with failing to deliver on the patient benefits of these new technologies, the biggest of which is posed by data siloing. The Minerva Initiative has been designed to enable the public good of deep phenotyping while mitigating these ethical risks. Its open structure, enabling collaboration and data sharing between individuals, clinicians, researchers and private enterprise, is key for delivering precision public health.
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http://dx.doi.org/10.3389/fgene.2019.00611DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6681681PMC
July 2019

Review of the phenotypic spectrum associated with haploinsufficiency of MYRF.

Am J Med Genet A 2019 07 8;179(7):1376-1382. Epub 2019 May 8.

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.

The myelin regulatory factor gene (MYRF) encodes a transcription factor that is widely expressed. There is increasing evidence that heterozygous loss-of-function variants in MYRF can lead to abnormal development of the heart, genitourinary tract, diaphragm, and lungs. Here, we searched a clinical database containing the results of 12,000 exome sequencing studies. We identified three previously unreported males with putatively deleterious variants in MYRF: one with a point mutation predicted to affect splicing and two with frameshift variants. In all cases where parental DNA was available, these variants were found to have arisen de novo. The phenotypes identified in these subjects included a variety of congenital heart defects (CHD) (hypoplastic left heart syndrome, scimitar syndrome, septal defects, and valvular anomalies), genitourinary anomalies (ambiguous genitalia, hypospadias, and cryptorchidism), congenital diaphragmatic hernia, and pulmonary hypoplasia. The phenotypes seen in our subjects overlap those described in individuals diagnosed with PAGOD syndrome [MIM# 202660], a clinically defined syndrome characterized by pulmonary artery and lung hypoplasia, agonadism, omphalocele, and diaphragmatic defects that can also be associated with hypoplastic left heart and scimitar syndrome. These cases provide additional evidence that haploinsufficiency of MYRF causes a genetic syndrome whose cardinal features include CHD, urogenital anomalies, congenital diaphragmatic hernia, and pulmonary hypoplasia. We also conclude that consideration should be given to screening individuals with PAGOD for pathogenic variants in MYRF, and that individuals with MYRF deficiency who survive the neonatal period should be monitored closely for developmental delay and intellectual disability.
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http://dx.doi.org/10.1002/ajmg.a.61182DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6557668PMC
July 2019

Missense Variants in the Histone Acetyltransferase Complex Component Gene TRRAP Cause Autism and Syndromic Intellectual Disability.

Authors:
Benjamin Cogné Sophie Ehresmann Eliane Beauregard-Lacroix Justine Rousseau Thomas Besnard Thomas Garcia Slavé Petrovski Shiri Avni Kirsty McWalter Patrick R Blackburn Stephan J Sanders Kévin Uguen Jacqueline Harris Julie S Cohen Moira Blyth Anna Lehman Jonathan Berg Mindy H Li Usha Kini Shelagh Joss Charlotte von der Lippe Christopher T Gordon Jennifer B Humberson Laurie Robak Daryl A Scott Vernon R Sutton Cara M Skraban Jennifer J Johnston Annapurna Poduri Magnus Nordenskjöld Vandana Shashi Erica H Gerkes Ernie M H F Bongers Christian Gilissen Yuri A Zarate Malin Kvarnung Kevin P Lally Peggy A Kulch Brina Daniels Andres Hernandez-Garcia Nicholas Stong Julie McGaughran Kyle Retterer Kristian Tveten Jennifer Sullivan Madeleine R Geisheker Asbjorg Stray-Pedersen Jennifer M Tarpinian Eric W Klee Julie C Sapp Jacob Zyskind Øystein L Holla Emma Bedoukian Francesca Filippini Anne Guimier Arnaud Picard Øyvind L Busk Jaya Punetha Rolph Pfundt Anna Lindstrand Ann Nordgren Fayth Kalb Megha Desai Ashley Harmon Ebanks Shalini N Jhangiani Tammie Dewan Zeynep H Coban Akdemir Aida Telegrafi Elaine H Zackai Amber Begtrup Xiaofei Song Annick Toutain Ingrid M Wentzensen Sylvie Odent Dominique Bonneau Xénia Latypova Wallid Deb Sylvia Redon Frédéric Bilan Marine Legendre Caitlin Troyer Kerri Whitlock Oana Caluseriu Marine I Murphree Pavel N Pichurin Katherine Agre Ralitza Gavrilova Tuula Rinne Meredith Park Catherine Shain Erin L Heinzen Rui Xiao Jeanne Amiel Stanislas Lyonnet Bertrand Isidor Leslie G Biesecker Dan Lowenstein Jennifer E Posey Anne-Sophie Denommé-Pichon Claude Férec Xiang-Jiao Yang Jill A Rosenfeld Brigitte Gilbert-Dussardier Séverine Audebert-Bellanger Richard Redon Holly A F Stessman Christoffer Nellaker Yaping Yang James R Lupski David B Goldstein Evan E Eichler Francois Bolduc Stéphane Bézieau Sébastien Küry Philippe M Campeau

Am J Hum Genet 2019 03 28;104(3):530-541. Epub 2019 Feb 28.

Centre Hospitalier Universitaire Sainte-Justine Research Centre, University of Montreal, Montreal, QC H3T 1C5, Canada; Department of Pediatrics, University of Montreal, Montreal, QC H3T1J4, Canada. Electronic address:

Acetylation of the lysine residues in histones and other DNA-binding proteins plays a major role in regulation of eukaryotic gene expression. This process is controlled by histone acetyltransferases (HATs/KATs) found in multiprotein complexes that are recruited to chromatin by the scaffolding subunit transformation/transcription domain-associated protein (TRRAP). TRRAP is evolutionarily conserved and is among the top five genes intolerant to missense variation. Through an international collaboration, 17 distinct de novo or apparently de novo variants were identified in TRRAP in 24 individuals. A strong genotype-phenotype correlation was observed with two distinct clinical spectra. The first is a complex, multi-systemic syndrome associated with various malformations of the brain, heart, kidneys, and genitourinary system and characterized by a wide range of intellectual functioning; a number of affected individuals have intellectual disability (ID) and markedly impaired basic life functions. Individuals with this phenotype had missense variants clustering around the c.3127G>A p.(Ala1043Thr) variant identified in five individuals. The second spectrum manifested with autism spectrum disorder (ASD) and/or ID and epilepsy. Facial dysmorphism was seen in both groups and included upslanted palpebral fissures, epicanthus, telecanthus, a wide nasal bridge and ridge, a broad and smooth philtrum, and a thin upper lip. RNA sequencing analysis of skin fibroblasts derived from affected individuals skin fibroblasts showed significant changes in the expression of several genes implicated in neuronal function and ion transport. Thus, we describe here the clinical spectrum associated with TRRAP pathogenic missense variants, and we suggest a genotype-phenotype correlation useful for clinical evaluation of the pathogenicity of the variants.
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http://dx.doi.org/10.1016/j.ajhg.2019.01.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6407527PMC
March 2019

Truncating Variants in NAA15 Are Associated with Variable Levels of Intellectual Disability, Autism Spectrum Disorder, and Congenital Anomalies.

Am J Hum Genet 2018 05 12;102(5):985-994. Epub 2018 Apr 12.

Stanley Institute for Cognitive Genomics, 1Bungtown Road, Cold Spring Harbor Laboratory, NY 11724, USA. Electronic address:

N-alpha-acetylation is a common co-translational protein modification that is essential for normal cell function in humans. We previously identified the genetic basis of an X-linked infantile lethal Mendelian disorder involving a c.109T>C (p.Ser37Pro) missense variant in NAA10, which encodes the catalytic subunit of the N-terminal acetyltransferase A (NatA) complex. The auxiliary subunit of the NatA complex, NAA15, is the dimeric binding partner for NAA10. Through a genotype-first approach with whole-exome or genome sequencing (WES/WGS) and targeted sequencing analysis, we identified and phenotypically characterized 38 individuals from 33 unrelated families with 25 different de novo or inherited, dominantly acting likely gene disrupting (LGD) variants in NAA15. Clinical features of affected individuals with LGD variants in NAA15 include variable levels of intellectual disability, delayed speech and motor milestones, and autism spectrum disorder. Additionally, mild craniofacial dysmorphology, congenital cardiac anomalies, and seizures are present in some subjects. RNA analysis in cell lines from two individuals showed degradation of the transcripts with LGD variants, probably as a result of nonsense-mediated decay. Functional assays in yeast confirmed a deleterious effect for two of the LGD variants in NAA15. Further supporting a mechanism of haploinsufficiency, individuals with copy-number variant (CNV) deletions involving NAA15 and surrounding genes can present with mild intellectual disability, mild dysmorphic features, motor delays, and decreased growth. We propose that defects in NatA-mediated N-terminal acetylation (NTA) lead to variable levels of neurodevelopmental disorders in humans, supporting the importance of the NatA complex in normal human development.
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http://dx.doi.org/10.1016/j.ajhg.2018.03.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5986698PMC
May 2018

De Novo Mutations in Protein Kinase Genes CAMK2A and CAMK2B Cause Intellectual Disability.

Authors:
Sébastien Küry Geeske M van Woerden Thomas Besnard Martina Proietti Onori Xénia Latypova Meghan C Towne Megan T Cho Trine E Prescott Melissa A Ploeg Stephan Sanders Holly A F Stessman Aurora Pujol Ben Distel Laurie A Robak Jonathan A Bernstein Anne-Sophie Denommé-Pichon Gaëtan Lesca Elizabeth A Sellars Jonathan Berg Wilfrid Carré Øyvind Løvold Busk Bregje W M van Bon Jeff L Waugh Matthew Deardorff George E Hoganson Katherine B Bosanko Diana S Johnson Tabib Dabir Øystein Lunde Holla Ajoy Sarkar Kristian Tveten Julitta de Bellescize Geir J Braathen Paulien A Terhal Dorothy K Grange Arie van Haeringen Christina Lam Ghayda Mirzaa Jennifer Burton Elizabeth J Bhoj Jessica Douglas Avni B Santani Addie I Nesbitt Katherine L Helbig Marisa V Andrews Amber Begtrup Sha Tang Koen L I van Gassen Jane Juusola Kimberly Foss Gregory M Enns Ute Moog Katrin Hinderhofer Nagarajan Paramasivam Sharyn Lincoln Brandon H Kusako Pierre Lindenbaum Eric Charpentier Catherine B Nowak Elouan Cherot Thomas Simonet Claudia A L Ruivenkamp Sihoun Hahn Catherine A Brownstein Fan Xia Sébastien Schmitt Wallid Deb Dominique Bonneau Mathilde Nizon Delphine Quinquis Jamel Chelly Gabrielle Rudolf Damien Sanlaville Philippe Parent Brigitte Gilbert-Dussardier Annick Toutain Vernon R Sutton Jenny Thies Lisenka E L M Peart-Vissers Pierre Boisseau Marie Vincent Andreas M Grabrucker Christèle Dubourg Wen-Hann Tan Nienke E Verbeek Martin Granzow Gijs W E Santen Jay Shendure Bertrand Isidor Laurent Pasquier Richard Redon Yaping Yang Matthew W State Tjitske Kleefstra Benjamin Cogné Slavé Petrovski Kyle Retterer Evan E Eichler Jill A Rosenfeld Pankaj B Agrawal Stéphane Bézieau Sylvie Odent Ype Elgersma Sandra Mercier

Am J Hum Genet 2017 Nov;101(5):768-788

CHU Nantes, Service de Génétique Médicale, 9 quai Moncousu, 44093 Nantes Cedex 1, France.

Calcium/calmodulin-dependent protein kinase II (CAMK2) is one of the first proteins shown to be essential for normal learning and synaptic plasticity in mice, but its requirement for human brain development has not yet been established. Through a multi-center collaborative study based on a whole-exome sequencing approach, we identified 19 exceedingly rare de novo CAMK2A or CAMK2B variants in 24 unrelated individuals with intellectual disability. Variants were assessed for their effect on CAMK2 function and on neuronal migration. For both CAMK2A and CAMK2B, we identified mutations that decreased or increased CAMK2 auto-phosphorylation at Thr286/Thr287. We further found that all mutations affecting auto-phosphorylation also affected neuronal migration, highlighting the importance of tightly regulated CAMK2 auto-phosphorylation in neuronal function and neurodevelopment. Our data establish the importance of CAMK2A and CAMK2B and their auto-phosphorylation in human brain function and expand the phenotypic spectrum of the disorders caused by variants in key players of the glutamatergic signaling pathway.
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http://dx.doi.org/10.1016/j.ajhg.2017.10.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5673671PMC
November 2017

Independent variant analysis of and in 38 Aicardi syndrome patients.

Mol Genet Genomic Med 2017 Mar 25;5(2):117-121. Epub 2017 Jan 25.

Department of Obstetrics and GynecologyBaylor College of MedicineHoustonTexas; Jan and Dan Duncan Neurological Research InstituteTexas Children's HospitalHoustonTexas; Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexas.

Background: Aicardi syndrome is a severe neurodevelopmental disorder characterized by infantile spasms, typical chorioretinal lacunae, agenesis of the corpus callosum, and other neuronal migration defects. It has been reported recently that de novo variants in and each may cause Aicardi syndrome in a single individual of a small cohort of females with this clinical diagnosis. These data were interpreted to suggest that the clinical diagnosis of Aicardi syndrome may be genetically heterogeneous.

Methods: To investigate this further, we sequenced and coding regions using DNA from 38 clinically well-characterized girls with Aicardi syndrome.

Results: We did not detect the previously reported or any other deleterious variants in any of the analyzed samples.

Conclusions: This suggests that the published variants represent either an extremely rare cause of Aicardi syndrome or an incidental finding.
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http://dx.doi.org/10.1002/mgg3.250DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5370232PMC
March 2017

Assessing sex assignment concordance with genotype and phenotype.

Int J Pediatr Endocrinol 2013 Mar 14;2013(1). Epub 2013 Mar 14.

Department of OBGYN, Division of Pediatric and Adolescent Gynecology, Baylor College of Medicine, Houston, TX, 77030, USA.

Objectives: To catalogue patients with DSD and to assess the concordance of genotype and phenotype with sex assignment at birth compared to sex assignment before and following assessment by a Gender Medicine Team (GMT) at one institution, as an initial step in formulating standardized guidelines for management of these conditions.

Design: After obtaining IRB approval, a retrospective chart review was conducted patients seen in the Gender Medicine Clinic (GMC) between 2006-2009 at Texas Children's Hospital (TCH), Houston, Texas. McNemar's test and Kappa agreement provided associations of various factors with sex assignment at birth prior to GMT assessment and after GMT assessment.

Participants: Forty-seven patients seen in the GMC with confirmed DSD.

Results: Forty-seven patients met the inclusion criteria. The mean age of the patients at the time of GMT evaluation was 9.1+/-6.1 years; 61.7% had male karyotype, and 38.3% had female karyotype; 51.1% had a male external phenotype, 42.6% had a female external phenotype, and 6.4% had phenotypic ambiguity. Sex assignment was concordant with genotype and phenotype in 63.8% and 86.4%, respectively of cases at the time of birth and in 76.6% and 97.7%, respectively, of cases after assessment by GMT.

Conclusion: Long-term outcomes are needed to establish standardized practice guidelines for decision-making.
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http://dx.doi.org/10.1186/1687-9856-2013-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3608956PMC
March 2013

The electroencephalogram in neonatal maple syrup urine disease: a case report.

Clin EEG Neurosci 2012 Jan;43(1):64-7

Section of Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.

Untreated maple syrup urine disease (MSUD) leads to encephalopathy in neonates and causes abnormalities on the electroencephalogram (EEG). A case is presented of MSUD with unique features consisting of a comb-like rhythm before the therapy and its disappearance with therapy is presented. This case illustrates the potential use of the EEG in the identification of this specific cause of a neonatal encephalopathy.
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http://dx.doi.org/10.1177/1550059411429521DOI Listing
January 2012

19q13.11 cryptic deletion: description of two new cases and indication for a role of WTIP haploinsufficiency in hypospadias.

Eur J Hum Genet 2012 Aug 29;20(8):852-6. Epub 2012 Feb 29.

Department of Molecular Medicine, Medical Genetics, University of Pavia, Pavia, Italy.

Developmental delay/intellectual disabilities, speech disturbance, pre- and postnatal growth retardation, microcephaly, signs of ectodermal dysplasia, and genital malformations in males (hypospadias) represent the phenotypic core of the recent emerging 19q13.11 deletion syndrome. Using array-CGH for genome-wide screening we detected an interstitial deletion of chromosome band 19q13.11 in two patients exhibiting the recognizable pattern of malformations as described in other instances of this submicroscopic genomic imbalance. The deletion detected in our patients has been compared with previously reported cases leading to the refinement of the minimal overlapping region (MOR) for this microdeletion syndrome to 324 kb. This region encompasses five genes: four zinc finger (ZNF) genes belonging to the KRAB-ZNF subfamily (ZNF302, ZNF181, ZNF599, and ZNF30) and LOC400685. On the basis of our male patient 1 and on further six male cases of the literature, we also highlighted that larger 19q13.11 deletions including the Wilms tumor interacting protein (WTIP) gene, proximal to the MOR, results in hypospadias making this gene a possible candidate for this genital abnormality due to its well-known interaction with WT1. Although the mechanism underlying the phenotypic effects of copy number alterations involving KRAB-ZNF genes at 19q13.11 has not clearly been established, we suggest their haploinsufficiency as the most likely candidate for the phenotypic core of the 19q13.11 deletion syndrome. In addition, we hypothesized WTIP gene haploinsufficiency as responsible for hypospadias.
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http://dx.doi.org/10.1038/ejhg.2012.19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3400733PMC
August 2012

Oral rapamycin in the treatment of patients with hamartoma syndromes and PTEN mutation.

Pediatr Blood Cancer 2011 Aug 25;57(2):321-3. Epub 2011 Feb 25.

Department of Pediatrics, Section of Hematology Oncology, Saint Peter's University Hospital, New Brunswick, New Jersey 08901, USA.

Bannayan-Riley-Ruvacalba syndrome (BRRS) belongs to the PTEN hamartoma tumor syndromes and is characterized by a high risk of malignancy in early adulthood added to local destructive effects of hamartomas in childhood. There is no standard treatment for this condition and patients are usually offered symptomatic surgical relief. Rapamycin has been reported to be effective in the management of other conditions associated with PTEN mutation. We report here a case of BRRS in a 6-year-old male with progressive loss of function of left hand and forearm associated with pain. He was treated with oral rapamycin and regained pain-free full mobility.
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http://dx.doi.org/10.1002/pbc.23098DOI Listing
August 2011

Cranio-meta-diaphyseal dysplasia: 25 year follow-up and review of literature.

Am J Med Genet A 2010 Sep;152A(9):2335-8

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.

We report here on a 25-year follow-up of cranio-meta-diaphyseal dysplasia in a 31-year-old Caucasian male, who was reported in the literature at the age of 8 years [Langer et al. (1991); Skeletal Radiol 20:37-41]. He has hyperostotic craniofacial features with protruding lower jaw and midface hypoplasia. He has the typical radiographic features of wide long tubular bones without normal metaphyseal flaring and wide short tubular bones without normal diaphyseal constriction. We describe here his clinical and radiological findings and compare his case with those published in the literature. He is the oldest reported patient with this disorder giving some insight into the natural history of this rare skeletal dysplasia.
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http://dx.doi.org/10.1002/ajmg.a.33582DOI Listing
September 2010

Mental retardation linked to mutations in the HSD17B10 gene interfering with neurosteroid and isoleucine metabolism.

Proc Natl Acad Sci U S A 2009 Sep 17;106(35):14820-4. Epub 2009 Aug 17.

Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA.

Mutations in the HSD17B10 gene were identified in two previously described mentally retarded males. A point mutation c.776G>C was found from a survivor (SV), whereas a potent mutation, c.419C>T, was identified in another deceased case (SF) with undetectable hydroxysteroid (17beta) dehydrogenase 10 (HSD10) activity. Protein levels of mutant HSD10(R130C) in patient SF and HSD10(E249Q) in patient SV were about half that of HSD10 in normal controls. The E249Q mutation appears to affect HSD10 subunit interactions, resulting in an allosteric regulatory enzyme. For catalyzing the oxidation of allopregnanolone by NAD+ the Hill coefficient of the mutant enzyme is approximately 1.3. HSD10(E249Q) was unable to catalyze the dehydrogenation of 2-methyl-3-hydroxybutyryl-CoA and the oxidation of allopregnanolone, a positive modulator of the gamma-aminobutyric acid type A receptor, at low substrate concentrations. Neurosteroid homeostasis is critical for normal cognitive development, and there is increasing evidence that a blockade of isoleucine catabolism alone does not commonly cause developmental disabilities. The results support the theory that an imbalance in neurosteroid metabolism could be a major cause of the neurological handicap associated with hydroxysteroid (17beta) dehydrogenase 10 deficiency.
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http://dx.doi.org/10.1073/pnas.0902377106DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2728107PMC
September 2009

Microduplications of 22q11.2 are frequently inherited and are associated with variable phenotypes.

Genet Med 2008 Apr;10(4):267-77

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA.

Purpose: Genomic rearrangements of chromosome 22q11.2, including the microdeletion associated with DiGeorge/velocardiofacial syndrome, are mediated by nonallelic homologous recombination between region-specific low-copy repeats. To date, only a small number of patients with 22q11.2 microduplication have been identified.

Methods: We report the identification by array-comparative genomic hybridization of 14 individuals from eight families who harbor microduplications within the 22q11.2 region.

Results: We have now observed a variety of microduplications, including the typical common approximately 3-Mb microduplication, approximately 1.5-Mb nested duplication, and smaller microduplications within and distal to the DiGeorge/velocardiofacial syndrome region, consistent with nonallelic homologous recombination using distinct low-copy repeats in the 22q11.2 DiGeorge/velocardiofacial syndrome region. These microduplications likely represent the predicted reciprocal rearrangements to the microdeletions characterized in the 22q11.2 region. The phenotypes seen in these individuals are generally mild and highly variable; familial transmission is frequently observed.

Conclusions: These findings highlight the unbiased ability of array-comparative genomic hybridization to identify genomic imbalances and further define the molecular etiology and clinical phenotypes seen in microduplication 22q11.2 syndrome. Our findings also further support that the 22q11.2 region is highly dynamic with frequent rearrangements using alternative low-copy repeats as recombination substrates.
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http://dx.doi.org/10.1097/GIM.0b013e31816b64c2DOI Listing
April 2008

Low-level mosaicism of trisomy 14: phenotypic and molecular characterization.

Am J Med Genet A 2008 Jun;146A(11):1395-405

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA.

Trisomy 14 mosaicism is a rare cytogenetic abnormality with a defined and recognizable clinical phenotype. We present a detailed clinical history and physical findings of five patients with low-level mosaicism of trisomy 14 detected by array-based comparative genomic hybridization (array-CGH) analysis or by routine chromosome analysis. These patients exhibited growth and developmental delays with variable severity, congenital anomalies, pigmentary skin lesions, and dysmorphic features. The phenotype of our patients was compared with previously described cases. This report suggests that trisomy 14 mosaicism may be more common than has been previously appreciated and also illustrates the important application of array-CGH to detect low-level mosaic chromosome abnormalities. We predict that a wider application of the array-CGH technology will significantly increase the detection rate of low-level mosaicism and will subsequently improve our ability to provide a diagnosis for patients with dysmorphic features, congenital anomalies, and developmental delay.
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http://dx.doi.org/10.1002/ajmg.a.32287DOI Listing
June 2008

Ethical and legal implications of genetic testing in androgen insensitivity syndrome.

J Pediatr 2007 Apr;150(4):434-8

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.

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http://dx.doi.org/10.1016/j.jpeds.2006.12.037DOI Listing
April 2007