Matthew James Barrett

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In addition to minimizing native and non-native protein aggregations, heat shock proteins (HSPs) regulate programmed cell death pathways. Members of this conserved protein family are in general activated by oxidative stress, and likely help maintain viability under this stress condition. To further our understanding of heat shock protein physiology, we(More)
Leucine rich repeat kinase (LRRK2) G2019S mutations are presumed to cause PD through a toxic gain of function of the protein kinase. Small molecule kinase inhibitors have been developed for the treatment of certain cancers, and some antioncogenic agents such as sunitinib, may nonspecifically inhibit LRRK2. Few studies, however, have assessed cancer risk in(More)
Mutations in the glucocerebrosidase (GBA1) gene, the most common genetic contributor to Parkinson's disease (PD), are associated with an increased risk of PD in heterozygous and homozygous carriers. While glucocerebrosidase enzyme (GCase) activity is consistently low in Gaucher disease, there is a range of leukocyte GCase activity in healthy heterozygous(More)
Velocardiofacial syndrome, also known as DiGeorge syndrome, is a multisystem genetic disorder caused by microdeletion of 3.0 megabases (Mb) of DNA on the long arm of chromosome 22. Recently, 22q11.2 deletion syndrome (22q11.2DS) has been recognized as a potential risk factor for the development of Parkinson’s disease (PD). We report on a patient with(More)
BACKGROUND The objective of this study was to confirm whether an association between handedness and the side of symptom onset exists and to evaluate the impact of this association on specific clinical characteristics of Parkinson's disease (PD). METHODS 1173 PD patients were identified from a clinical database. Patients with asymmetrical onset (n=1015)(More)
G2019S mutations in the LRRK2 gene are responsible for up to 18% of PD in individuals of Jewish descent. While a male preponderance of Parkinson disease (PD) has been consistently reported, this gender difference is not noted in LRRK2 G2019S mutation carriers. In order to test whether there is an increased genetic component in women of Jewish background in(More)
BACKGROUND Heterozygous glucocerebrosidase (GBA) mutations are the leading genetic risk factor for Parkinson disease, yet imaging correlates, particularly transcranial sonography, have not been extensively described. METHODS To determine whether GBA mutation heterozygotes with Parkinson disease demonstrate hyperechogenicity of the substantia nigra,(More)
BACKGROUND Meta-analysis of genome-wide association studies have implicated multiple single nucleotide polymorphisms (SNPs) and associated genes with Alzheimer disease. The role of these SNPs in cognitive impairment in Parkinson disease (PD) remains incompletely evaluated. OBJECTIVE The objective of this study was to test alleles associated with risk of(More)
We studied 25-hydroxyvitamin D (vitamin D) levels in patients with amyotrophic lateral sclerosis (ALS) and the effect of vitamin D supplementation. Vitamin D levels were checked in 37 consecutive patients with ALS. Demographic data, vitamin D supplementation, change in Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) score, and side effects(More)
Cytochrome oxidase (COX) activity varies between individuals and low activities associate with Alzheimer's disease. Whether genetic heterogeneity influences function of this multimeric enzyme is unknown. To explore this we sequenced three mitochondrial DNA (mtDNA) and ten nuclear COX subunit genes from at least 50 individuals. 20% had non-synonymous mtDNA(More)