Lack of C9orf72 repeat expansion in Taiwanese patients with mixed neurodegenerative disorders
Journal
Frontiers in Neurology
Journal Volume
43926
Date Issued
2014
Author(s)
Abstract
Background: The hexanucleotide repeat expansion in intron 1 of the C9orf72 gene is recognized as the most common genetic cause of frontotemporal dementia (FTD). There are overlapping clinical and pathological characteristics between FTD and Parkinsonism syndrome, and some FTD patients may present with Parkinsonism. The aim of this study was to analyze the hexanucleotide repeat numbers of C9orf72 gene in a mixed Taiwanese cohort with FTD, Parkinsonism syndrome, Parkinson's disease (PD), and Alzheimer's dementia (AD). Method: The number of hexanucleotide repeats was estimated in a total of 482 patients with mixed neurodegenerative disorders and 485 control subjects, using a two-step repeat-primed polymerase chain reaction-based genotyping strategy. The individual groups of patients included patients with Parkinsonism syndrome (n = 95), familial PD (n = 109), young-onset PD (n = 201), FTD (n = 9), sporadic AD (n = 61), and early-onset AD (n = 7). Results: We did not identify any pathogenic repeats (>30 repeats) of C9orf72 in either the patients or control subjects. However, we found one young-onset PD patient and one control subject that each had an intermediate number of repeats (25 and 21 repeats, respectively). The clinical phenotype of the young-onset PD in this patient was similar to typical idiopathic PD without additional features, and the patient responded well to levodopa treatment. Conclusion: The repeat expansion in C9orf72 is not a common cause of PD, Parkinsonism syndrome, or dementia in our population. Further studies are needed to investigate the clinical and biological significance of intermediate repeats in C9orf72. ? 2014 Lin, Chen, Chiu, Lin and Wu.
SDGs
Other Subjects
levodopa; adult; aged; Alzheimer disease; article; C9orf72 gene; CAG repeat; cohort analysis; controlled study; ethnic group; female; frontotemporal dementia; gene; genetic analysis; genotyping technique; hexanucleotide repeat expansion; human; major clinical study; male; onset age; Parkinson disease; parkinsonism; phenotype; polymerase chain reaction; Taiwan; Taiwanese
Publisher
Frontiers Media SA
Type
journal article