Lack of mutations in spinocerebellar ataxia type 2 and 3 genes in a Taiwanese (Ethnic Chinese) cohort of familial and early-onset parkinsonism
Journal
American Journal of Medical Genetics, Part B: Neuropsychiatric Genetics
Journal Volume
144
Journal Issue
4
Pages
434-438
Date Issued
2007
Author(s)
Abstract
Recent reports suggest that CAG triplet expansions of spinocerebellar ataxia type 2 and 3 (SCA2 and SCA3) genes are the cause of typical levodoparesponsive Parkinson's disease (PD) in familial cases, several of which were ethnic Chinese. To investigate the role of SCA2 and SCA3 mutations in Chinese familial and early-onset PD patients, we analyzed CAG triplet repeat expansions of SCA2 and SCA3 genes in a cohort of 73 Taiwanese/Ethnic Chinese familial and early-onset PD patients [mean age at onset 42.70 ± 7.17 years (mean±SD)]. Thirteen of them (17.8%) had positive family history. All patients received comprehensive clinical evaluation including a thorough neurological examination, laboratory tests, and neuroimaging studies to exclude secondary causes and atypical parkinsonism. The CAG repeat length in these genes was determined using polymerase chain reaction polyacrylamide gel electrophoresis. SCA2 gene CAG repeats ranged from 15 to 26 repeats with a median of 20, and SCA3 gene CAG repeats ranged from 15 to 40 with a median of 15. No long pathogenic repeats were found in either SCA2 or SCA3, although borderline CAG repeat number was detected in the SCA3 gene of four patients. Thus, mutations of SCA2 or SCA3 did not play a major role in familial or early-onset PD in our study cohort. PD patients without autosomal dominant family history or obvious cerebellar ataxia should not be candidates for routine screening of SCA2 or SCA3 mutations for cost-effectiveness. ? 2007 Wiley-Liss, Inc.
SDGs
Other Subjects
adenine; cytosine; guanine; adult; aged; article; Chinese; clinical article; clinical evaluation; cohort analysis; female; gene; gene function; gene mutation; gene sequence; human; laboratory test; male; neuroimaging; neurologic examination; nucleotide repeat; onset age; parkinsonism; polyacrylamide gel electrophoresis; polymerase chain reaction; priority journal; sca2 gene; sca3 gene; sequence analysis; Taiwan; Adult; Age of Onset; Aged; Asian Continental Ancestry Group; Cohort Studies; Female; Humans; Male; Middle Aged; Mutation; Nerve Tissue Proteins; Nuclear Proteins; Parkinsonian Disorders; Phenotype; Repressor Proteins; Taiwan; Trinucleotide Repeats
Type
journal article