FBXO7 mutations in Parkinson's disease and multiple system atrophy

Abstract

Mutations in the F-box only protein 7 (FBXO7) gene, located on chromosome 22q12-q13, have recently been identified as having distinct clinical features in patients with hereditary Parkinson's disease (PD). Pathologically, α-synuclein-positive inclusions have been identified using anti-FBXO7 antibody staining techniques. In the present study, we screened entire exons of FBXO7 from 271 patients (231 PD and 40 multiple system atrophy [MSA]), of which 221 samples were of Japanese origin. The PD patients (n = 231) comprised 31 autosomal dominant, 82 autosomal recessive, and 118 sporadic forms. The 40 cases of MSA consisted of 8 autosomal dominant, 2 autosomal recessive, and 30 sporadic forms. We detected a Turkish patient with autosomal recessive inheritance, harboring a homozygous truncating mutation, Arg498Stop (p.R498X), in the FBXO7 gene. Consequently, we evaluated her and assessed the correlation between her clinical manifestations and genotypic analysis, although the FBXO7 p.R498X gene has lower frequency than others. Her age at onset was 17 years, and she clinically manifested with progressive parkinsonism and cognitive decline. In contrast, no pathogenic mutations in FBXO7 among PD and MSA patients of Japanese or other ethnicities were observed. Based on recent literature, we reviewed and compared the clinical findings and population differences between documented FBXO7 cases.

Keywords: FBXO7; Genetics; Multiple system atrophy; Parkinson's disease.