title: Mitochondrial DNA Haplogroups and the Risk of Sporadic Parkinson's Disease in Han Chinese.
abstract: BACKGROUND
  Mitochondrial dysfunction is linked to the pathogenesis of Parkinson's disease (PD). However, the precise role of mitochondrial DNA (mtDNA) variations is obscure. On the other hand, mtDNA haplogroups have been inconsistently reported to modify the risk of PD among different population. Here, we try to explore the relationship between mtDNA haplogroups and sporadic PD in a Han Chinese population.
  
  
  METHODS
  Nine single-nucleotide polymorphisms, which define the major Asian mtDNA haplogroups (A, B, C, D, F, G), were detected via polymerase chain reaction-restriction fragment length polymorphism or denaturing polyacrylamide gel electrophoresis in 279 sporadic PD patients and 510 matched controls of Han population.
  
  
  RESULTS
  Overall, the distribution of mtDNA haplogroups did not show any significant differences between patients and controls. However, after stratification by age at onset, the frequency of haplogroup B was significantly lower in patients with early-onset PD (EOPD) compared to the controls (odds ratio [OR] =0.225, 95% confidence interval [CI]: 0.082-0.619, P = 0.004), while other haplogroups did not show significant differences. After stratification by age at examination, among subjects younger than 50 years of age: Haplogroup B also showed a lower frequency in PD cases (OR = 0.146, 95% CI: 0.030-0.715, P = 0.018) while haplogroup D presented a higher risk of PD (OR = 3.579, 95% CI: 1.112-11.523, P = 0.033), other haplogroups also did not show significant differences in the group.
  
  
  CONCLUSIONS
  Our study indicates that haplogroup B might confer a lower risk for EOPD and people younger than 50 years in Han Chinese, while haplogroup D probably lead a higher risk of PD in people younger than 50 years of age. In brief, particular Asian mtDNA haplogroups likely play a role in the pathogenesis of PD among Han Chinese.
authors.forename: Ya-Fang
authors.initials: YF
authors.lastname: Chen
authors.forename: Wan-Jin
authors.initials: WJ
authors.lastname: Chen
authors.forename: Xiao-Zhen
authors.initials: XZ
authors.lastname: Lin
authors.forename: Qi-Jie
authors.initials: QJ
authors.lastname: Zhang
authors.forename: Jiang-Ping
authors.initials: JP
authors.lastname: Cai
authors.forename: Chia-Wei
authors.initials: CW
authors.lastname: Liou
authors.affiliation: Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University; Fujian Key Laboratory of Molecular Neurology, Fuzhou, Fujian 350005, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000235:genetics*; D010375:Pedigree; D020641:Polymorphism, Single Nucleotide / Q000235:genetics
chemical_list: D004272:DNA, Mitochondrial