Publications by authors named "Penelope Hogarth"

48 Publications

Consensus clinical management guideline for beta-propeller protein-associated neurodegeneration.

Dev Med Child Neurol 2021 Aug 4. Epub 2021 Aug 4.

Departments of Molecular and Medical Genetics, Pediatrics, and Neurology, Oregon Health & Science University, Portland, OR, USA.

This review provides recommendations for the evaluation and management of individuals with beta-propeller protein-associated neurodegeneration (BPAN). BPAN is one of several neurodegenerative disorders with brain iron accumulation along with pantothenate kinase-associated neurodegeneration, PLA2G6-associated neurodegeneration, mitochondrial membrane protein-associated neurodegeneration, fatty acid hydroxylase-associated neurodegeneration, and COASY protein-associated neurodegeneration. BPAN typically presents with global developmental delay and epilepsy in childhood, which is followed by the onset of dystonia and parkinsonism in mid-adolescence or adulthood. BPAN is an X-linked dominant disorder caused by pathogenic variants in WDR45, resulting in a broad clinical phenotype and imaging spectrum. This review, informed by an evaluation of the literature and expert opinion, discusses the clinical phenotype and progression of the disease, imaging findings, epilepsy features, and genetics, and proposes an approach to the initial evaluation and management of disease manifestations across the life span in individuals with BPAN.
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http://dx.doi.org/10.1111/dmcn.14980DOI Listing
August 2021

Magnetic resonance imaging pattern recognition in childhood bilateral basal ganglia disorders.

Brain Commun 2020 26;2(2):fcaa178. Epub 2020 Oct 26.

Kids Neuroscience Centre, The Children's Hospital at Westmead, Westmead, NSW 2145, Australia.

Bilateral basal ganglia abnormalities on MRI are observed in a wide variety of childhood disorders. MRI pattern recognition can enable rationalization of investigations and also complement clinical and molecular findings, particularly confirming genomic findings and also enabling new gene discovery. A pattern recognition approach in children with bilateral basal ganglia abnormalities on brain MRI was undertaken in this international multicentre cohort study. Three hundred and five MRI scans belonging to 201 children with 34 different disorders were rated using a standard radiological scoring proforma. In addition, literature review on MRI patterns was undertaken in these 34 disorders and 59 additional disorders reported with bilateral basal ganglia MRI abnormalities. Cluster analysis on first MRI findings from the study cohort grouped them into four clusters: Cluster 1-T-weighted hyperintensities in the putamen; Cluster 2-T-weighted hyperintensities or increased MRI susceptibility in the globus pallidus; Cluster 3-T-weighted hyperintensities in the globus pallidus, brainstem and cerebellum with diffusion restriction; Cluster 4-T-weighted hyperintensities in the basal ganglia. The 34 diagnostic categories included in this study showed dominant clustering in one of the above four clusters. Inflammatory disorders grouped together in Cluster 1. Mitochondrial and other neurometabolic disorders were distributed across clusters 1, 2 and 3, according to lesions dominantly affecting the (Cluster 1: glutaric aciduria type 1, propionic acidaemia, 3-methylglutaconic aciduria with deafness, encephalopathy and Leigh-like syndrome and thiamine responsive basal ganglia disease associated with ), pallidum (Cluster 2: methylmalonic acidaemia, Kearns Sayre syndrome, pyruvate dehydrogenase complex deficiency and succinic semialdehyde dehydrogenase deficiency) or pallidum, brainstem and cerebellum (Cluster 3: vigabatrin toxicity, Krabbe disease). The Cluster 4 pattern was exemplified by distinct T-weighted hyperintensities in the basal ganglia and other brain regions in genetically determined hypermanganesemia due to and . Within the clusters, distinctive basal ganglia MRI patterns were noted in acquired disorders such as cerebral palsy due to hypoxic ischaemic encephalopathy in full-term babies, kernicterus and vigabatrin toxicity and in rare genetic disorders such as 3-methylglutaconic aciduria with deafness, encephalopathy and Leigh-like syndrome, thiamine responsive basal ganglia disease, pantothenate kinase-associated neurodegeneration, and hypermanganesemia. Integrated findings from the study cohort and literature review were used to propose a diagnostic algorithm to approach bilateral basal ganglia abnormalities on MRI. After integrating clinical summaries and MRI findings from the literature review, we developed a prototypic decision-making electronic tool to be tested using further cohorts and clinical practice.
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http://dx.doi.org/10.1093/braincomms/fcaa178DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7891249PMC
October 2020

Brain MRI Pattern Recognition in Neurodegeneration With Brain Iron Accumulation.

Front Neurol 2020 10;11:1024. Epub 2020 Sep 10.

Departments of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, United States.

Most neurodegeneration with brain iron accumulation (NBIA) disorders can be distinguished by identifying characteristic changes on magnetic resonance imaging (MRI) in combination with clinical findings. However, a significant number of patients with an NBIA disorder confirmed by genetic testing have MRI features that are atypical for their specific disease. The appearance of specific MRI patterns depends on the stage of the disease and the patient's age at evaluation. MRI interpretation can be challenging because of heterogeneously acquired MRI datasets, individual interpreter bias, and lack of quantitative data. Therefore, optimal acquisition and interpretation of MRI data are needed to better define MRI phenotypes in NBIA disorders. The stepwise approach outlined here may help to identify NBIA disorders and delineate the natural course of MRI-identified changes.
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http://dx.doi.org/10.3389/fneur.2020.01024DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7511538PMC
September 2020

4'-Phosphopantetheine corrects CoA, iron, and dopamine metabolic defects in mammalian models of PKAN.

EMBO Mol Med 2019 12 29;11(12):e10489. Epub 2019 Oct 29.

Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, OR, USA.

Pantothenate kinase-associated neurodegeneration (PKAN) is an inborn error of CoA metabolism causing dystonia, parkinsonism, and brain iron accumulation. Lack of a good mammalian model has impeded studies of pathogenesis and development of rational therapeutics. We took a new approach to investigating an existing mouse mutant of Pank2 and found that isolating the disease-vulnerable brain revealed regional perturbations in CoA metabolism, iron homeostasis, and dopamine metabolism and functional defects in complex I and pyruvate dehydrogenase. Feeding mice a CoA pathway intermediate, 4'-phosphopantetheine, normalized levels of the CoA-, iron-, and dopamine-related biomarkers as well as activities of mitochondrial enzymes. Human cell changes also were recovered by 4'-phosphopantetheine. We can mechanistically link a defect in CoA metabolism to these secondary effects via the activation of mitochondrial acyl carrier protein, which is essential to oxidative phosphorylation, iron-sulfur cluster biogenesis, and mitochondrial fatty acid synthesis. We demonstrate the fidelity of our model in recapitulating features of the human disease. Moreover, we identify pharmacodynamic biomarkers, provide insights into disease pathogenesis, and offer evidence for 4'-phosphopantetheine as a candidate therapeutic for PKAN.
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http://dx.doi.org/10.15252/emmm.201910489DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6895607PMC
December 2019

Transportation innovation to aid Parkinson disease trial recruitment.

Contemp Clin Trials Commun 2019 Dec 10;16:100449. Epub 2019 Sep 10.

Beth Israel Deaconess Medical Center, Boston, MA, USA.

Among the barriers to participation in clinical trials, transportation to and from study sites may be a prominent issue. Patients with Parkinson's disease have unique circumstances that add to the barriers including dementia, loss of driving ability, timing of medications, impact of reduced mobility, and bowel and bladder concerns. We sought to alleviate some of the burden of transportation by setting up pre-arranged rides through a third-party ride sharing service. This pilot project was established to assess feasibility and to explore the possibility that reducing the transportation burden may enhance participation in studies. One out of three academic sites was successful in setting up this service, and surveyed participants on the impact of this service. In general, study participants who opted into the ride-sharing service felt it made the process easier and less stressful. Most participants agreed that they are more likely to participate in another study if transportation was provided. This short-term pilot intervention suggests that participants were satisfied with a ride sharing service to help with their medical transportation needs, but larger studies that include data collection about retention are needed.
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http://dx.doi.org/10.1016/j.conctc.2019.100449DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6804741PMC
December 2019

Motor phenotype classification in moderate to advanced PD in BioFIND study.

Parkinsonism Relat Disord 2019 08 23;65:178-183. Epub 2019 Jun 23.

Fresco Institute for Parkinson's and Movement Disorders, Department of Neurology, NYU Langone Health, New York, NY, USA. Electronic address:

Background: Three motor phenotypes have been described in PD: postural instability and gait difficulty (PIGD) dominant, tremor-dominant (TD), and indeterminate (IND) subtype. These phenotypes have been associated with different cognitive trajectories, motor outcomes, and biomarkers profiles. However, whether motor subtype classifications change with treatment and disease progression is not well established.

Methods: To evaluate motor subtype ratio changes, we used the chi-square test for the off and on state motor subtypes for 115 PD participants in the BioFIND study and used repeated-measures analyses to evaluate longitudinal changes in 162 PD participants with five-year follow-up in the PPMI study.

Results: PIGD and TD subtypes in moderate to advanced PD participants change with dopaminergic agents. For those who shifted subtypes, improvement in tremor accounted for the transition of 15 (25.4%) TD participants, while the lack of tremor improvement along with minimal changes in PIGD score resulted in changes for eight (19.0%) PIGD individuals. Analyses of PPMI data revealed that all three subgroups had a significant decrease in subtype ratio with disease progression and a significant decline in subtype ratio occurred only in the TD subgroup with dopaminergic agents. The impact of dopaminergic medication effect on subtype shift for each visit was also more notable with disease advancement.

Conclusions: Motor subtypes are not fixed but change with progression of the disease and with treatment. Improvement in tremor was the main contributor to motor phenotype transitions in the BioFIND cohort. A more stable classification system for subtypes based on underlying biological differences is desirable.
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http://dx.doi.org/10.1016/j.parkreldis.2019.06.017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6774826PMC
August 2019

Safety and efficacy of deferiprone for pantothenate kinase-associated neurodegeneration: a randomised, double-blind, controlled trial and an open-label extension study.

Lancet Neurol 2019 07;18(7):631-642

Department of Hematology Oncology, UCSF Benioff Children's Hospital and Research Center Oakland, Oakland, CA, USA.

Background: Pantothenate kinase-associated neurodegeneration (PKAN) is a rare genetic disorder characterised by progressive generalised dystonia and brain iron accumulation. We assessed whether the iron chelator deferiprone can reduce brain iron and slow disease progression.

Methods: We did an 18-month, randomised, double-blind, placebo-controlled trial (TIRCON2012V1), followed by a pre-planned 18-month, open-label extension study, in patients with PKAN in four hospitals in Germany, Italy, England, and the USA. Patients aged 4 years or older with a genetically confirmed diagnosis of PKAN, a total score of at least 3 points on the Barry-Albright Dystonia (BAD) scale, and no evidence of iron deficiency, neutropenia, or abnormal hepatic or renal function, were randomly allocated (2:1) to receive an oral solution of either deferiprone (30 mg/kg per day divided into two equal doses) or placebo for 18 months. Randomisation was done with a centralised computer random number generator and with stratification based on age group at onset of symptoms. Patients were allocated to groups by a randomisation team not masked for study intervention that was independent of the study. Patients, caregivers, and investigators were masked to treatment allocation. Co-primary endpoints were the change from baseline to month 18 in the total score on the BAD scale (which measures severity of dystonia in eight body regions) and the score at month 18 on the Patient Global Impression of Improvement (PGI-I) scale, which is a patient-reported interpretation of symptom improvement. Efficacy analyses were done on all patients who received at least one dose of the study drug and who provided a baseline and at least one post-baseline efficacy assessment. Safety analyses were done for all patients who received at least one dose of the study drug. Patients who completed the randomised trial were eligible to enrol in a single-arm, open-label extension study of another 18 months, in which all participants received deferiprone with the same regimen as the main study. The trial was registered on ClinicalTrials.gov, number NCT01741532, and EudraCT, number 2012-000845-11.

Findings: Following a screening of 100 prospective patients, 88 were randomly assigned to the deferiprone group (n=58) or placebo group (n=30) between Dec 13, 2012, and April 21, 2015. Of these, 76 patients completed the study (49 in the deferiprone group and 27 in the placebo group). After 18 months, the BAD score worsened by a mean of 2·48 points (SE 0·63) in patients in the deferiprone group versus 3·99 points (0·82) for patients in the control group (difference -1·51 points, 95% CI -3·19 to 0·16, p=0·076). No subjective change was detected as assessed by the PGI-I scale: mean scores at month 18 were 4·6 points (SE 0·3) for patients in the deferiprone group versus 4·7 points (0·4) for those in the placebo group (p=0·728). In the extension study, patients continuing deferiprone retained a similar rate of disease progression as assessed by the BAD scale (1·9 points [0·5] in the first 18 months vs 1·4 points [0·4] in the second 18 months, p=0·268), whereas progression in patients switching from placebo to deferiprone seemed to slow (4·4 points [1·1] vs 1·4 points [0·9], p=0·021). Patients did not detect a change in their condition after the additional 18 months of treatment as assessed by the PGI-I scale, with mean scores of 4·1 points [0·2] in the deferiprone-deferiprone group and of 4·7 points [0·3] in the placebo-deferiprone group. Deferiprone was well tolerated and adverse events were similar between the treatment groups, except for anaemia, which was seen in 12 (21%) of 58 patients in the deferiprone group, but was not seen in any patients in the placebo group. No patient discontinued therapy because of anaemia, and three discontinued because of moderate neutropenia. There was one death in each group of the extension study and both were secondary to aspiration. Neither of these events was considered related to deferiprone use.

Interpretation: Deferiprone was well tolerated, achieved target engagement (lowering of iron in the basal ganglia), and seemed to somewhat slow disease progression at 18 months, although not significantly, as assessed by the BAD scale. These findings were corroborated by the results of an additional 18 months of treatment in the extension study. The subjective PGI-I scale was largely unchanged during both study periods, indicating that might not be an adequate tool for assessment of disease progression in patients with PKAN. Our trial provides the first indication of a decrease in disease progression in patients with neurodegeneration with brain iron accumulation. The extensive information collected and long follow-up of patients in the trial will improve the definition of appropriate endpoints, increase the understanding of the natural history, and thus help to shape the design of future trials in this ultra-orphan disease.

Funding: European Commission, US Food and Drug Administration, and ApoPharma Inc.
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http://dx.doi.org/10.1016/S1474-4422(19)30142-5DOI Listing
July 2019

Autosomal dominant mitochondrial membrane protein-associated neurodegeneration (MPAN).

Mol Genet Genomic Med 2019 07 13;7(7):e00736. Epub 2019 May 13.

Molecular & Medical Genetics, Pediatrics and Neurology, Oregon Health & Science University, Portland, Oregon.

Background: Mitochondrial membrane protein-associated neurodegeneration (MPAN) is caused by pathogenic sequence variants in C19orf12. Autosomal recessive inheritance has been demonstrated. We present evidence of autosomal dominant MPAN and propose a mechanism to explain these cases.

Methods: Two large families with apparently dominant MPAN were investigated; additional singleton cases of MPAN were identified. Gene sequencing and multiplex ligation-dependent probe amplification were used to characterize the causative sequence variants in C19orf12. Post-mortem brain from affected subjects was examined.

Results: In two multi-generation non-consanguineous families, we identified different nonsense sequence variations in C19orf12 that segregate with the MPAN phenotype. Brain pathology was similar to that of autosomal recessive MPAN. We additionally identified a preponderance of cases with single heterozygous pathogenic sequence variants, including two with de novo changes.

Conclusions: We present three lines of clinical evidence to demonstrate that MPAN can manifest as a result of only one pathogenic C19orf12 sequence variant. We propose that truncated C19orf12 proteins, resulting from nonsense variants in the final exon in our autosomal dominant cohort, impair function of the normal protein produced from the non-mutated allele via a dominant negative mechanism and cause loss of function. These findings impact the clinical diagnostic evaluation and counseling.
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http://dx.doi.org/10.1002/mgg3.736DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6625130PMC
July 2019

Assessment of an Objective Method of Dyskinesia Measurement in Parkinson's Disease.

Mov Disord Clin Pract 2018 Mar-Apr;5(2):160-164. Epub 2018 Mar 2.

Oregon Health & Science University Portland Oregon USA.

Background: The goal of this study was to validate an objective method of measuring levodopa induced dyskinesia in Parkinson's disease (PD).

Methods: To characterize agreement between the clinician-based measure and a force plate, we assessed dyskinesia in PD subjects participating in a randomized and blinded clinical trial of an adenosine A2A anatagonist. Convergent validity and intra-class correlations were evaluated between the objective force plate measure and clinician assessments.

Results: All measures correlated across time and detected differences in treatments.

Conclusion: Our results indicate that objective measure from a force plate is in scale agreement with clinical ratings of dyskinesia severity, indicating it as a reliable method to measure LID objectively but with greater resolution to detect changes in LID.
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http://dx.doi.org/10.1002/mdc3.12583DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6174364PMC
March 2018

Neurodegeneration with brain iron accumulation.

Handb Clin Neurol 2018 ;147:293-305

Departments of Molecular and Medical Genetics and Neurology, Oregon Health and Science University, Portland, OR, United States.

Neurodegeneration with brain iron accumulation (NBIA) comprises a clinically and genetically heterogeneous group of disorders affecting children and adults. These rare disorders are often first suspected when increased basal ganglia iron is observed on brain magnetic resonance imaging. For the majority of NBIA disorders the genetic basis has been delineated, and clinical testing is available. The four most common NBIA disorders include pantothenate kinase-associated neurodegeneration (PKAN) due to mutations in PANK2, phospholipase A-associated neurodegeneration caused by mutation in PLA2G6, mitochondrial membrane protein-associated neurodegeneration from mutations in C19orf12, and beta-propeller protein-associated neurodegeneration due to mutations in WDR45. The ultrarare NBIA disorders are caused by mutations in CoASY, ATP13A2, and FA2H (causing CoA synthase protein-associated neurodegeneration, Kufor-Rakeb disease, and fatty acid hydroxylase-associated neurodegeneration, respectively). Together, these genes account for disease in approximately 85% of patients diagnosed with an NBIA disorder. New NBIA genes are being recognized with increasing frequency as a result of whole-exome sequencing, which is also facilitating early ascertainment of patients whose phenotype is often nonspecific.
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http://dx.doi.org/10.1016/B978-0-444-63233-3.00019-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8235601PMC
July 2018

Cerebrospinal fluid, plasma, and saliva in the BioFIND study: Relationships among biomarkers and Parkinson's disease Features.

Mov Disord 2018 02 4;33(2):282-288. Epub 2017 Dec 4.

Division of Movement Disorders, Department of Neurology, Columbia University Medical Center, New York, New York, USA.

Objective: Examine relationships among neurodegenerative biomarkers and PD motor and nonmotor symptoms.

Background: CSF alpha-synuclein is decreased in PD versus healthy controls, but whether plasma and saliva alpha-synuclein differentiate these groups is controversial. Correlations of alpha-synuclein among biofluids (CSF, plasma, saliva) or biomarkers (eg, beta-amyloid, tau [total, phosphorylated]) are not fully understood. The relationships of these biomarkers with PD clinical features remain unclear.

Methods: BioFIND, a cross-sectional, observational study, examines clinical and biomarker characteristics in moderate-advanced PD and matched healthy controls. We compared alpha-synuclein concentrations across diagnosis, biofluids, and CSF biomarkers. Correlations of CSF biomarkers and MDS-UPDRS, motor phenotype, MoCA, and rapid eye movement sleep behavior disorder questionnaire scores in PD were examined.

Results: CSF alpha-synuclein was lower in PD versus controls (P = .01), controlling for age, gender, and education. Plasma and saliva alpha-synuclein did not differ between PD and controls, and alpha-synuclein did not significantly correlate among biofluids. CSF beta-amyloid was lower in PD versus controls (P < .01), and correlated weakly with MoCA recall scores (r = 0.23, P = .02). CSF alpha-synuclein was lower in the postural instability/gait difficulty phenotype than other motor phenotypes (P < .01). No CSF biomarkers predicted or correlated with total motor or rapid eye movement sleep behavior disorder scores. CSF alpha-synuclein correlated with beta-amyloid , total-tau, and phosphorylated-tau (r = 0.41, 0.81, 0.43, respectively; Ps < .001).

Conclusion: Lower CSF alpha-synuclein is associated with diagnosis and motor phenotype in moderate-advanced PD. Plasma and saliva alpha-synuclein neither correlate with CSF alpha-synuclein, nor distinguish PD from controls. CSF beta-amyloid remains a potential biomarker for cognitive impairment in PD. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
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http://dx.doi.org/10.1002/mds.27232DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5836918PMC
February 2018

Changes in Red Blood Cell membrane lipid composition: A new perspective into the pathogenesis of PKAN.

Mol Genet Metab 2017 06 18;121(2):180-189. Epub 2017 Apr 18.

Unit of Molecular Neurogenetics, Pierfranco and Luisa Mariani Centre for the Study of Mitochondrial Disorders in Children, Foundation IRCCS Neurological Institute C. Besta, Via Temolo 4, 20126 Milan, Italy. Electronic address:

Pantothenate Kinase-Associated Neurodegeneration (PKAN) is a form of Neurodegeneration with Brain Iron Accumulation (NBIA) associated with mutations in the pantothenate kinase 2 gene (PANK2). The PANK2 catalyzes the first step of coenzyme A (CoA) biosynthesis, a pathway producing an essential cofactor that plays a key role in energy and lipid metabolism. The majority of PANK2 mutations reduces or abolishes the activity of the enzyme. In around 10% of cases with PKAN, the presence of deformed red blood cells with thorny protrusions in the circulation has been detected. Changes in membrane protein expression and assembly during erythropoiesis were previously explored in patients with PKAN. However, data on red blood cell membrane phospholipid organization are still missing in this disease. In this study, we performed lipidomic analysis on red blood cells from Italian patients affected by PKAN with a particular interest in membrane physico-chemical properties. We showed an increased number of small red blood cells together with membrane phospholipid alteration, particularly a significant increase in sphingomyelin (SM)/phosphatidylcholine (PC) and SM/phosphatidylethanolamine (PE) ratios, in subjects with PKAN. The membrane structural abnormalities were associated with membrane fluidity perturbation. These morphological and functional characteristics of red blood cells in patients with PKAN offer new possible tools in order to shed light on the pathogenesis of the disease and to possibly identify further biomarkers for clinical studies.
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http://dx.doi.org/10.1016/j.ymgme.2017.04.006DOI Listing
June 2017

Consensus clinical management guideline for pantothenate kinase-associated neurodegeneration (PKAN).

Mol Genet Metab 2017 03 27;120(3):278-287. Epub 2016 Dec 27.

Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, USA; Department of Neurology, Oregon Health & Science University, Portland, USA.

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http://dx.doi.org/10.1016/j.ymgme.2016.11.004DOI Listing
March 2017

MECR Mutations Cause Childhood-Onset Dystonia and Optic Atrophy, a Mitochondrial Fatty Acid Synthesis Disorder.

Am J Hum Genet 2016 Dec 3;99(6):1229-1244. Epub 2016 Nov 3.

The Sackler School of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel; Institute of Rare Diseases, The Danek Gertner Institute of Human Genetics, Chaim Sheba Medical Center, 52621 Ramat Gan, Israel.

Mitochondrial fatty acid synthesis (mtFAS) is an evolutionarily conserved pathway essential for the function of the respiratory chain and several mitochondrial enzyme complexes. We report here a unique neurometabolic human disorder caused by defective mtFAS. Seven individuals from five unrelated families presented with childhood-onset dystonia, optic atrophy, and basal ganglia signal abnormalities on MRI. All affected individuals were found to harbor recessive mutations in MECR encoding the mitochondrial trans-2-enoyl-coenzyme A-reductase involved in human mtFAS. All six mutations are extremely rare in the general population, segregate with the disease in the families, and are predicted to be deleterious. The nonsense c.855T>G (p.Tyr285), c.247_250del (p.Asn83Hisfs4), and splice site c.830+2_830+3insT mutations lead to C-terminal truncation variants of MECR. The missense c.695G>A (p.Gly232Glu), c.854A>G (p.Tyr285Cys), and c.772C>T (p.Arg258Trp) mutations involve conserved amino acid residues, are located within the cofactor binding domain, and are predicted by structural analysis to have a destabilizing effect. Yeast modeling and complementation studies validated the pathogenicity of the MECR mutations. Fibroblast cell lines from affected individuals displayed reduced levels of both MECR and lipoylated proteins as well as defective respiration. These results suggest that mutations in MECR cause a distinct human disorder of the mtFAS pathway. The observation of decreased lipoylation raises the possibility of a potential therapeutic strategy.
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http://dx.doi.org/10.1016/j.ajhg.2016.09.021DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5142118PMC
December 2016

The BioFIND study: Characteristics of a clinically typical Parkinson's disease biomarker cohort.

Mov Disord 2016 06 26;31(6):924-32. Epub 2016 Apr 26.

The Michael J. Fox Foundation for Parkinson's Research, New York, New York, USA.

Background: Identifying PD-specific biomarkers in biofluids will greatly aid in diagnosis, monitoring progression, and therapeutic interventions. PD biomarkers have been limited by poor discriminatory power, partly driven by heterogeneity of the disease, variability of collection protocols, and focus on de novo, unmedicated patients. Thus, a platform for biomarker discovery and validation in well-characterized, clinically typical, moderate to advanced PD cohorts is critically needed.

Methods: BioFIND (Fox Investigation for New Discovery of Biomarkers in Parkinson's Disease) is a cross-sectional, multicenter biomarker study that established a repository of clinical data, blood, DNA, RNA, CSF, saliva, and urine samples from 118 moderate to advanced PD and 88 healthy control subjects. Inclusion criteria were designed to maximize diagnostic specificity by selecting participants with clinically typical PD symptoms, and clinical data and biospecimen collection utilized standardized procedures to minimize variability across sites.

Results: We present the study methodology and data on the cohort's clinical characteristics. Motor scores and biospecimen samples including plasma are available for practically defined off and on states and thus enable testing the effects of PD medications on biomarkers. Other biospecimens are available from off state PD assessments and from controls.

Conclusion: Our cohort provides a valuable resource for biomarker discovery and validation in PD. Clinical data and biospecimens, available through The Michael J. Fox Foundation for Parkinson's Research and the National Institute of Neurological Disorders and Stroke, can serve as a platform for discovering biomarkers in clinically typical PD and comparisons across PD's broad and heterogeneous spectrum. © 2016 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5021110PMC
http://dx.doi.org/10.1002/mds.26613DOI Listing
June 2016

Clinical-Genetic Associations in the Prospective Huntington at Risk Observational Study (PHAROS): Implications for Clinical Trials.

JAMA Neurol 2016 Jan;73(1):102-10

Wake Forest University School of Medicine, Winston-Salem, North Carolina.

Importance: Identifying measures that are associated with the cytosine-adenine-guanine (CAG) expansion in individuals before diagnosis of Huntington disease (HD) has implications for designing clinical trials.

Objective: To identify the earliest features associated with the motor diagnosis of HD in the Prospective Huntington at Risk Observational Study (PHAROS).

Design, Setting, And Participants: A prospective, multicenter, longitudinal cohort study was conducted at 43 US and Canadian Huntington Study Group research sites from July 9, 1999, through December 17, 2009. Participants included 983 unaffected adults at risk for HD who had chosen to remain unaware of their mutation status. Baseline comparability between CAG expansion (≥37 repeats) and nonexpansion (<37 repeats) groups was assessed. All participants and investigators were blinded to individual CAG analysis. A repeated-measures analysis adjusting for age and sex was used to assess the divergence of the linear trend between the expanded and nonexpanded groups. Data were analyzed from April 27, 2010, to September 3, 2013.

Exposure: Huntington disease mutation status in individuals with CAG expansion vs without CAG expansion.

Main Outcomes And Measures: Unified Huntington's Disease Rating Scale motor (score range, 0-124; higher scores indicate greater impairment), cognitive (symbol digits modality is the total number of correct responses in 90 seconds; lower scores indicate greater impairment), behavioral (score range, 0-176; higher scores indicate greater behavioral symptoms), and functional (Total Functional Capacity score range, 0-13; lower scores indicate reduced functional ability) domains were assessed at baseline and every 9 months up to a maximum of 10 years.

Results: Among the 983 research participants at risk for HD in the longitudinal cohort, 345 (35.1%) carried the CAG expansion and 638 (64.9%) did not. The mean (SD) duration of follow-up was 5.8 (3.0) years. At baseline, participants with expansions had more impaired motor (3.0 [4.2] vs 1.9 [2.8]; P < .001), cognitive (P < .05 for all measures except Verbal Fluency, P = .52), and behavioral domain scores (9.4 [11.4] vs 6.5 [8.5]; P < .001) but not significantly different measures of functional capacity (12.9 [0.3] vs 13.0 [0.2]; P = .23). With findings reported as mean slope (95% CI), in the longitudinal analyses, participants with CAG expansions showed significant worsening in motor (0.84 [0.73 to 0.95] vs 0.03 [-0.05 to 0.11]), cognitive (-0.54 [-0.67 to -0.40] vs 0.22 [0.12 to 0.32]), and functional (-0.08 [-0.09 to -0.06] vs -0.01 [-0.02 to 0]) measures compared with those without expansion (P < .001 for all); behavioral domain scores did not diverge significantly between groups.

Conclusions And Relevance: Using these prospectively accrued clinical data, relatively large treatment effects would be required to mount a randomized, placebo-controlled clinical trial involving premanifest HD individuals who carry the CAG expansion.
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http://dx.doi.org/10.1001/jamaneurol.2015.2736DOI Listing
January 2016

Pallidal neuronal apolipoprotein E in pantothenate kinase-associated neurodegeneration recapitulates ischemic injury to the globus pallidus.

Mol Genet Metab 2015 Dec 31;116(4):289-97. Epub 2015 Oct 31.

Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR 97239, United States.

Pantothenate kinase-associated neurodegeneration (PKAN) is a progressive movement disorder that is due to mutations in PANK2. Pathologically, it is a member of a class of diseases known as neurodegeneration with brain iron accumulation (NBIA) and features increased tissue iron and ubiquitinated proteinaceous aggregates in the globus pallidus. We have previously determined that these aggregates represent condensed residue derived from degenerated pallidal neurons. However, the protein content, other than ubiquitin, of these aggregates remains unknown. In the present study, we performed biochemical and immunohistochemical studies to characterize these aggregates and found them to be enriched in apolipoprotein E that is poorly soluble in detergent solutions. However, we did not determine a significant association between APOE genotype and the clinical phenotype of disease in our database of 81 cases. Rather, we frequently identified similar ubiquitin- and apolipoprotein E-enriched lesions in these neurons in non-PKAN patients in the penumbrae of remote infarcts that involve the globus pallidus, and occasionally in other brain sites that contain large γ-aminobutyric acid (GABA)ergic neurons. Our findings, taken together, suggest that tissue or cellular hypoxic/ischemic injury within the globus pallidus may underlie the pathogenesis of PKAN.
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http://dx.doi.org/10.1016/j.ymgme.2015.10.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4688119PMC
December 2015

Novel WDR45 Mutation and Pathognomonic BPAN Imaging in a Young Female With Mild Cognitive Delay.

Pediatrics 2015 Sep 3;136(3):e714-7. Epub 2015 Aug 3.

Division of Neurology, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Canada; and

β-propeller protein-associated neurodegeneration (BPAN) is a recently identified X-linked dominant form of neurodegeneration with brain iron accumulation caused by mutations in the WDR45 gene. BPAN commonly presents as global developmental delay in childhood with rapid onset of parkinsonism and dementia in early adulthood and associated pathognomonic changes seen on brain MRI. In this case report, we present a pediatric patient with mild cognitive delay and pathognomonic MRI changes indicative of BPAN preceding neurologic deterioration who is found to have a novel de novo mutation in the WDR45 gene.
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http://dx.doi.org/10.1542/peds.2015-0750DOI Listing
September 2015

Domains and correlates of clinical balance impairment associated with Huntington's disease.

Gait Posture 2015 Mar 9;41(3):867-70. Epub 2015 Mar 9.

Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA.

This study sought to (a) determine the domains of clinical balance impairments associated with Huntington's disease (HD), and (b) evaluate associations between balance test scores and other disease-related impairments. Eighteen subjects with genetically definite HD and 17 age-matched control subjects were evaluated on the Mini-BESTest for their clinical balance impairments as well as the Unified HD Rating Scale (UHDRS) motor and total functional capacity scales, Activity-Specific Balance Confidence (ABC) Scale-short form, Montreal Cognitive Assessment (MoCA), and Symbol Digit Modalities Test (SDMT). Results showed that subjects with HD exhibited significantly lower total Mini-BESTest scores than subjects without HD (mean (95% CI)=76 (64-87)% with HD, 98 (96-99)% without HD; p=0.0011). Mini-BESTest item scores were significantly lower for subjects with HD on one-leg stance, postural responses, standing with eyes closed on foam, and dual-task timed up-and-go. Mini-BESTest scores significantly correlated with UHDRS motor (r(2)=0.68; p=0.00003) and total functional capacity (r(2)=0.75; p=0.000006) scores as well as with scores on the ABC short form (r(2)=0.45; p=0.0024), SDMT (r(2)=0.42; p=0.0036), and MoCA (r(2)=0.23; p=0.046) assessments. This study, therefore, demonstrates that balance impairments associated with HD span domains of anticipatory postural adjustments, postural responses, stance in challenging sensory conditions, and gait. Although preliminary, clinical balance impairment appears to be an efficient proxy evaluation of multiple HD-related factors due to associations with functional capacity, other motor impairments, balance confidence, and cognitive abilities.
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http://dx.doi.org/10.1016/j.gaitpost.2015.02.018DOI Listing
March 2015

Neurodegeneration with brain iron accumulation: diagnosis and management.

Authors:
Penelope Hogarth

J Mov Disord 2015 Jan 13;8(1):1-13. Epub 2015 Jan 13.

Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR, USA.

Neurodegeneration with brain iron accumulation (NBIA) encompasses a group of inherited disorders that share the clinical features of an extrapyramidal movement disorder accompanied by varying degrees of intellectual disability and abnormal iron deposition in the basal ganglia. The genetic basis of ten forms of NBIA is now known. The clinical features of NBIA range from rapid global neurodevelopmental regression in infancy to mild parkinsonism with minimal cognitive impairment in adulthood, with wide variation seen between and within the specific NBIA sub-type. This review describes the clinical presentations, imaging findings, pathologic features, and treatment considerations for this heterogeneous group of disorders.
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http://dx.doi.org/10.14802/jmd.14034DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4298713PMC
January 2015

The effect of deep brain stimulation randomized by site on balance in Parkinson's disease.

Mov Disord 2014 Jun 14;29(7):949-53. Epub 2014 Feb 14.

Department of Neurology, Oregon Health & Science University, Portland, Oregon, USA.

Background: The effect of the surgical site of DBS on balance and gait in Parkinson's Disease (PD) is uncertain. This is the first double-blind study of subjects randomized to either the STN (N = 14) or GPi (N = 14) who were assessed on a range of clinical balance measures.

Methods: Balance testing occurred before and 6 months postsurgery. A control PD group was tested over the same period without surgery (N = 9). All subjects were tested on and off medication and DBS subjects were also tested on and off DBS. The Postural Instability and Gait Disability items of the UPDRS and additional functional tests, which we call the Balance and Gait scale, were assessed. Activities of Balance Confidence and Activities of Daily Living questionnaires were also recorded.

Results: Balance was not different between the best-treated states before and after DBS surgery for both sites. Switching DBS on improved balance scores, and scores further improved with medication, compared to the off state. The GPi group showed improved performance in the postsurgery off state and better ratings of balance confidence after surgery, compared to the STN group.

Conclusions: Clinical measures of balance function for both the STN and GPi sites showed that balance did not improve beyond the best medically treated state before surgery. Both clinical balance testing in the off/off state and self-reported balance confidence after surgery showed better performance in the GPi than the STN group.
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http://dx.doi.org/10.1002/mds.25831DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4057940PMC
June 2014

Metabolism and energy requirements in pantothenate kinase-associated neurodegeneration.

Mol Genet Metab 2013 Nov 1;110(3):336-41. Epub 2013 Jul 1.

Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, USA.

Pantothenate kinase-associated neurodegeneration (PKAN) is an autosomal recessive disorder of coenzyme A homeostasis caused by defects in the mitochondrial pantothenate kinase 2. Patients with PKAN present with a progressive neurological decline and brain iron accumulation, but general energy balance and nutrition status among these patients has not been reported. To determine if defects in PANK2 change basic energy metabolism in humans, we measured body composition, resting energy expenditure, dietary intake, and blood metabolites among 16 subjects with PKAN. Subjects had a broad range of disease severity but, despite the essential role of coenzyme A in energy metabolism, the subjects had remarkably normal body composition, dietary intake and energy metabolism compared to population normal values. We did observe increased resting energy expenditure associated with disease severity, suggesting increased energy needs later in the disease process, and elevated urinary mevalonate levels.
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http://dx.doi.org/10.1016/j.ymgme.2013.06.017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6059611PMC
November 2013

β-Propeller protein-associated neurodegeneration: a new X-linked dominant disorder with brain iron accumulation.

Brain 2013 Jun 17;136(Pt 6):1708-17. Epub 2013 May 17.

Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR 97239, USA.

Neurodegenerative disorders with high iron in the basal ganglia encompass an expanding collection of single gene disorders collectively known as neurodegeneration with brain iron accumulation. These disorders can largely be distinguished from one another by their associated clinical and neuroimaging features. The aim of this study was to define the phenotype that is associated with mutations in WDR45, a new causative gene for neurodegeneration with brain iron accumulation located on the X chromosome. The study subjects consisted of WDR45 mutation-positive individuals identified after screening a large international cohort of patients with idiopathic neurodegeneration with brain iron accumulation. Their records were reviewed, including longitudinal clinical, laboratory and imaging data. Twenty-three mutation-positive subjects were identified (20 females). The natural history of their disease was remarkably uniform: global developmental delay in childhood and further regression in early adulthood with progressive dystonia, parkinsonism and dementia. Common early comorbidities included seizures, spasticity and disordered sleep. The symptoms of parkinsonism improved with l-DOPA; however, nearly all patients experienced early motor fluctuations that quickly progressed to disabling dyskinesias, warranting discontinuation of l-DOPA. Brain magnetic resonance imaging showed iron in the substantia nigra and globus pallidus, with a 'halo' of T1 hyperintense signal in the substantia nigra. All patients harboured de novo mutations in WDR45, encoding a beta-propeller protein postulated to play a role in autophagy. Beta-propeller protein-associated neurodegeneration, the only X-linked disorder of neurodegeneration with brain iron accumulation, is associated with de novo mutations in WDR45 and is recognizable by a unique combination of clinical, natural history and neuroimaging features.
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http://dx.doi.org/10.1093/brain/awt095DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3673459PMC
June 2013

Clinical features of neurodegeneration with brain iron accumulation due to a C19orf12 gene mutation.

Mov Disord 2013 Sep 13;28(10):1462-3. Epub 2013 Mar 13.

Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois, USA.

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http://dx.doi.org/10.1002/mds.25410DOI Listing
September 2013

New NBIA subtype: genetic, clinical, pathologic, and radiographic features of MPAN.

Neurology 2013 Jan 26;80(3):268-75. Epub 2012 Dec 26.

Department of Neurology, Oregon Health & Science University, Portland, USA.

Objective: To assess the frequency of mutations in C19orf12 in the greater neurodegeneration with brain iron accumulation (NBIA) population and further characterize the associated phenotype.

Methods: Samples from 161 individuals with idiopathic NBIA were screened, and C19orf12 mutations were identified in 23 subjects. Direct examinations were completed on 8 of these individuals, and medical records were reviewed on all 23. Histochemical and immunohistochemical studies were performed on brain tissue from one deceased subject.

Results: A variety of mutations were detected in this cohort, in addition to the Eastern European founder mutation described previously. The characteristic clinical features of mitochondrial membrane protein-associated neurodegeneration (MPAN) across all age groups include cognitive decline progressing to dementia, prominent neuropsychiatric abnormalities, and a motor neuronopathy. A distinctive pattern of brain iron accumulation is universal. Neuropathologic studies revealed neuronal loss, widespread iron deposits, and eosinophilic spheroidal structures in the basal ganglia. Lewy neurites were present in the globus pallidus, and Lewy bodies and neurites were widespread in other areas of the corpus striatum and midbrain structures.

Conclusions: MPAN is caused by mutations in C19orf12 leading to NBIA and prominent, widespread Lewy body pathology. The clinical phenotype is recognizable and distinctive, and joins pantothenate kinase-associated neurodegeneration and PLA2G6-associated neurodegeneration as one of the major forms of NBIA.
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http://dx.doi.org/10.1212/WNL.0b013e31827e07beDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3589182PMC
January 2013
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