title: [Correlation between ABO blood type gene and attention-deficit hyperactivity disorder in children].
abstract: OBJECTIVE
  To investigate the correlation between ABO blood type gene and attention-deficit hyperactivity disorder (ADHD) in children.
  
  
  METHODS
  ABO blood types were determined using glass sheet method in 96 children with ADHD and their parents. O gene was identified using polymerase chain reaction and restriction fragment length polymorphism in patients with A or B blood type. Haplotype-based haplotype relative risk (HHRR), transmission-disequilibrium test (TDT) and Chi-square test were used to examine the association between ABO gene and ADHD.
  
  
  RESULTS
  TDT results showed significant differences in the allele of ABO between the 96 children with ADHD and within-family controls (chi2=6.017, df=2, P< 0.05). Chi-square test results showed differences in the allele of A and B (chi2=3.289, df=1, P=0.07) as well as O and B (chi2=3.629, df=1, P=0.057 ) between ADHD children and within-family controls. The frequencies of O and A genes were higher than that of B gene in ADHD children.
  
  
  CONCLUSIONS
  There was correlation between ABO blood type gene and ADHD in children. The risk of ADHD is increased in the presence of alleles O and A, but the risk is reduced in the presence of allele B.
authors.affiliation: Department of Pediatrics, 260th Hospital Affiliated to the Forth Military Medical University, Shijianzhuang, China.
authors.forename: Xian-Su
authors.initials: XS
authors.lastname: Guo
authors.forename: Bao-Quan
authors.initials: BQ
authors.lastname: Jiao
authors.forename: Tong
authors.initials: T
authors.lastname: Xu
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D000293:Adolescent; D000483:Alleles; D001289:Attention Deficit Disorder with Hyperactivity / Q000097:blood* / Q000235:genetics; D002648:Child; D005260:Female; D006239:Haplotypes; D006801:Humans; D008297:Male
chemical_list: D000017:ABO Blood-Group System