title: Association between the epidermal growth factor gene and intelligence in major depression patients.
abstract: OBJECTIVE
  To study the association between the epidermal growth factor (EGF) gene and intelligence in patients with major depression.
  
  
  METHODS
  Intelligence measurement using Wechsler Adult Intelligence Scale (WAIS) was performed on 120 unrelated patients with major depression and 46 control subjects. Blood was collected from all subjects for extraction of genomic DNA. Four single nucleotide polymorphisms (SNPs) in the EGF gene were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI- TOF-MS).
  
  
  RESULTS
  Mean scores of both score lang and score task, two subtests in WAIS, differed significantly between major depression patients and controls (P<0.0001). Quantitative trait analysis showed that the genotype of rs2250724 was closely associated with score lang and score task in major depression patients. The associations were still significant after 10 000 permutations.
  
  
  CONCLUSIONS
  Although preliminary, our results provide evidence for association between the EGF gene and intelligence in patients with major depression. Genetic variation in the EGF gene may increase the susceptibility of major depression.
authors.affiliation: National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100005, China.
authors.forename: Wen-min
authors.initials: WM
authors.lastname: Tian
authors.forename: Ke-ran
authors.initials: KR
authors.lastname: Zhang
authors.forename: Juan
authors.initials: J
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Shen
authors.forename: Qi
authors.initials: Q
authors.lastname: Xu
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000235:genetics*; D004815:Epidermal Growth Factor / Q000235:genetics*; D005260:Female; D006801:Humans; D007360:Intelligence / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D004815:Epidermal Growth Factor