Lack of association between TOR1A and THAP1 mutations and sporadic adult-onset primary focal dystonia in a Chinese population

• To assess the association of TOR1A and THAP1 within AOPFD.
• A total of 248 subjects (117 patients vs. 131 healthy controls) were included.
• TOR1A mutation has little, if any, contribution to AOPFD.
• No association between TOR1A variants (rs2296793, rs1801968) and AOPFD was found.
• The results of our study were confirmed by pooled analysis.

ObjectiveTOR1A (torsin family 1, member A) and THAP1 (THAP domain containing, apoptosis associated protein 1) are two candidate genes that have been reported to be linked to adult-onset primary dystonia. However, the overall results have been inconsistent, likely because primary dystonia may have subtype-specific genetic risk factors. The aim of our study was to assess the association of TOR1A and THAP1 with adult-onset primary focal dystonia (AOPFD), the most common subtype of primary dystonia.MethodsA total of 248 subjects, comprising 117 AOPFD patients and 131 healthy controls, were included in our study. All coding exons of TOR1A and THAP1 were initially analyzed in the 117 patients. Subsequently, we investigated the association of two common TOR1A variants (rs2296793, rs1801968) with AOPFD in a Chinese population (117 patients versus 131 controls) and performed a pooled analysis by combining our data with previously published data.ResultsNo mutation of TOR1A and THAP1 was found other than two TOR1A variants (rs2296793, rs1801968), which have been previously reported in AOPFD patients. There were no statistically significant differences in the minor allele frequency (MAF) and genotype frequency between AOPFD and controls in our Chinese population (P > 0.05). This result was confirmed by pooled analysis of multi-ethnic groups.ConclusionOur study suggested that there might not be an association between TOR1A or THAP1 and patients with AOPFD.