Objective: To detect PINK1 gene mutations and study the clinical features in Chinese patients with autosomal recessive early-onset parkinsonism (AREP) type 6.
Methods: PINK1 gene mutations were detected using polymerase chain reaction (PCR), DNA sequence analysis, and restriction enzyme digestion analysis in 11 index probands of 11 AREP families.
Results: Two novel point mutations in PINK1 gene, C938T in exon four, leading to substitution of a threonine for methionine codon at amino acid 313 (T313M) and C1474T in exon seven introducing a stop codon at amino acid 492 (R492Stop), were found in two families. In another family, a synonymous mutation (Y454Y) was detected. The clinical features in patients with PINK1 mutations included early onset, slow disease progression, hyperreflexia, diurnal fluctuations with sleep benefit, and good response to levodopa. However, dyskinesias related to levodopa treatment were absent.
Conclusion: PINK1 gene mutations are a common cause of AREP. PARK6 pedigrees have been firstly identified in Chinese Mainland. Clinical heterogeneity exists in PARK6.