POSTER NO: 446

Mutation screening and association analysis of the Parkin gene in sporadic Han Chinese Parkinson's disease patients from South West China

¹Rong Peng, ¹Yinru Gou, ¹Qiang Yuan, ²Tao Li, ²Helen Latsoudis, ¹Guanggu Yuan, ¹Deru Luo, ¹Xiehe Liu, ²David A. Collier
¹Department of Neurology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, P.R China, ²Department of Psychological Medicine, Institute of Psychiatry, De Crespigny Park, Denmark Hill, London, SE5 8AF, UK

Various deletions and point mutations in the Parkin gene have been strongly associated with Parkinson's disease and parkinsonism, especially when onset is young. In this study, we screened 25 early-onset (<49 years of age) patients from a Han-Chinese population from South West China with 'sporadic' PD, for deletions and mutations in the Parkin gene. We found no deletion or point mutations in exon 1-12 of the Parkin gene using simple PCR amplification direct sequence analysis. We detected the known common Ser167Asn polymorphism and analysed it for association with sporadic PD. The Ser167Asn polymorphism was genotyped in 116 patients with sporadic PD and 124 controls, matched in age, gender and area of residence. There were significant differences between PD patients (161Asn 53.3 %) and controls (167Asn 35.1% ) (X2 = 6.54, p = 0.011, Odds ratio = 1.61, 95 % CI 1.10- 2.37). The genotype frequencies were also significantly different between PD patients (167Ser 24.1 %, 167Ser/Asn 58.6 %, 167Asn 17.3 %) and controls (167Ser 41.1 %, 167Ser/Asn 47.6 %, 167Asn 11.3 %) (X2= 8.14, p =0.017). The frequency of the 167Ser genotype was also significantly lower in PD patients than in controls, compared with that of other two genotypes combined (X2 = 7.84, p = 0.005, Odds ratio = 0.46, 95 % CI 0.25- 0.82). No significant differences in the frequencies of the allele and genotypes were found between two different groups of symptoms at onset (X2 = 0.191, p = 0.66, Odds ratio =1.12, 95 % CI 0.65- 1.95 ; X2 = 0.24, p = 0.887). There was no significant relationship between genotypes and age of onset ( p = 0.787). In summary, heterozygous deletion mutations and point mutations in exon 1-12 of the parkin gene were not detected in this Han-Chinese population, although we cannot exclude compound heterozygous deletions. In addition, our study suggests that the variant 167Asn allele increases the risk of developing sporadic PD.