title: An association study between DLGAP1 rs11081062 and EFNA5 rs26728 polymorphisms with obsessive-compulsive disorder in a Chinese Han population.
abstract: BACKGROUND
  A recent genome-wide association study indicated that the single nucleotide polymorphisms (SNPs) rs11081062 in DLGAP1 and rs26728 in EFNA5 were associated with obsessive-compulsive disorder (OCD) in Caucasians. The present case-control association study assessed the global relevance of these two SNPs with respect to OCD subtypes in a Chinese Han population.
  
  
  METHODS
  We recruited 320 OCD patients and 431 age- and sex-matched controls from a Chinese Han population. rs11081062 and rs26728 SNPs were genotyped by real-time TaqMan polymerase chain reaction, and the chi-squared test was used to compare allele and genotype frequencies of variants between the two groups.
  
  
  RESULTS
  No significant differences were found in allele or genotype frequencies of DLGAP1 rs11081062 and EFNA5 rs26728 between the OCD and control groups. Moreover, consistently negative results were observed when classifying by sex, onset age, and comorbidity. However, on analyzing OCD subphenotypes, significant associations were observed between rs11081062 and the presence of contamination obsessions and cleaning compulsions (χ (2)=7.724, P=0.021 by genotype; χ (2)=3.745, P=0.053 by allele; and χ (2)=0.821, P=0.365 by genotype, χ (2)=27.809, P=0.000 by allele, respectively), and rs26728 with the presence of repeating compulsions (χ (2)=8.285, P=0.004 by genotype; χ (2)=7.512, P=0.006 by allele).
  
  
  CONCLUSIONS
  Although we found no association between DLGAP1 rs11081062 and EFNA5 rs26728 SNPs with OCD in a Chinese Han population, obvious associations were observed with OCD subphenotypes. Therefore, it appears to be useful to divide OCD into more homogeneous subphenotypes to help understand the complex genetic basis of this disorder. Further investigations are needed to replicate these findings using larger sample sizes, different populations, and other polymorphisms.
authors.affiliation: Physiatry Department, The Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Psychiatry, Qingdao University, Qingdao, People's Republic of China.
authors.forename: Jiajia
authors.initials: J
authors.lastname: Cui
authors.affiliation: Department of Genetics, Medical College, Qingdao University, Qingdao, People's Republic of China.
authors.forename: Xiuhai
authors.initials: X
authors.lastname: Wang
authors.affiliation: The Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Ma
authors.affiliation: The Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Niu
authors.affiliation: Graduate School, Peking Union Medical College, Beijing, People's Republic of China ; National Research Institute for Family Planning, Beijing, People's Republic of China ; World Health Organization Collaborating Centre for Research in Human Reproduction, Beijing, People's Republic of China.
authors.forename: Xu
authors.initials: X
authors.lastname: Ma
authors.affiliation: Department of Psychiatry, Qingdao University, Qingdao, People's Republic of China ; The Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Prenatal Diagnosis Center, The Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China.
authors.forename: Shiguo
authors.initials: S
authors.lastname: Liu
keywords: DLGAP1; EFNA5; obsessive-compulsive disorder; polymorphism