title: [Association study of intelligence of attention deficit hyperactivity disorder children in China].
abstract: OBJECTIVE
  To investigate the association of 5-HT(2A) receptor gene (HTR2A)-1438A/G, Catechol-O-methyltransferase (COMT) gene Val158Met, Monoamine oxidase A ( MAOA ) gene 30 bp-VNTR(MAOA-uVNTR)polymorphisms, and the educational attainment level of the parents with the intelligence of attention deficit hyperactivity disorder (ADHD) in China.
  
  
  METHODS
  A total of 485 DSM-IV ADHD children of Chinese Han descent were included, both complete IQ evaluation, HTR2A-1438A/G, COMT gene Val158Met, and MAOA-uVNTR genotyping results were obtained. The quantitative traits of psychometric IQ were calculated by using the Chinese Wechsler Intelligence Scale for Children (C-WISC). The multifactor linear regression analysis was used to test the associated factors on intelligence.
  
  
  RESULTS
  Analyses revealed that ADHD children with low enzymatic activity (3R for males, 3R3R for females) of MAOA-uVNTR performed better on Full Scale IQ (FIQ) than did patients with high enzymatic activity (4R for males, 3R4R/4R4R for females) [(102.6+/-12.4) vs (100.3+/-11.7), P=0.078]. The patients with high-enzymatic activity (ValVal) of COMT gene Val158Met performed significantly better on FIQ than did patients with mid-low enzymatic activity (ValMet and MetMet)[(103.5+/-13.6) vs (100.5+/-11.5), P=0.036]. ADHD children with GG genotype of HTR2A-1438A/G performed significantly better on some aspects of C-WISC test (Full Scale IQ and Verbal Scale IQ) than did children with GA and AA genotypes [FIQ :(106.9+/-10.7) vs (100.7+/-12.3) vs (101.7+/-12.9), P=0.003; VIQ: (110.1+/-10.6) vs (103.5+/-12.1) vs (105.1+/-13.2), P=0.001]. The educational attainment level of the parents was associated with all the aspects of C-WISC test (Full Scale IQ, Verbal Scale IQ, and Performance Scale IQ). The multiple linear regression analysis showed that the genotype of HTR2A-1438A/G had significant correlation with FIQ, VIQ and PIQ; while the educational attainment level of the mother had significant correlation with FIQ and VIQ.
  
  
  CONCLUSIONS
  The HTR2A-1438A/G polymorphism and the educational attainment level of the mother were associated with the intelligence of ADHD children in China.
authors.affiliation: Department of Pediatrics, Peking University Institute of Mental Health; Key Laboratory of Mental Health, Ministry of Health, Beijing 100191, China.
authors.forename: Qiu-jin
authors.initials: QJ
authors.lastname: Qian
authors.forename: Yu-feng
authors.initials: YF
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Li-li
authors.initials: LL
authors.lastname: Guan
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.forename: Ning
authors.initials: N
authors.lastname: Ji
authors.forename: Lu
authors.initials: L
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000235:genetics* / Q000523:psychology*; D002648:Child; D002681:China; D004522:Educational Status; D005260:Female; D056726:Genetic Association Studies; D005838:Genotype; D006801:Humans; D007360:Intelligence; D007361:Intelligence Tests; D008297:Male; D009035:Mothers; D011110:Polymorphism, Genetic; D044402:Receptor, Serotonin, 5-HT2A / Q000235:genetics*
chemical_list: D044402:Receptor, Serotonin, 5-HT2A