title: The associations of SEA-alpha thalassemia 1, XmnI-Ggamma polymorphism and beta-globin gene mutations with the clinical severity of beta-thalassemia syndrome in northern Thailand.
abstract: BACKGROUND
  At least three genetic factors including beta-thalassemia mutations, alpha-thalassemia, and XmnI-Ggamma polymorphism were shown to modify clinical symptoms in beta-thalassemia disease.
  
  
  OBJECTIVE
  To determine associations of beta-thalassemia mutations, SEA-alpha thalassemia 1, and XmnI-Ggamma polymorphism, and clinical severity of beta-thalassemia in northern Thailand.
  
  
  METHODS
  Thirty-two beta-thalassemia major and 28 beta-thalassemia intermedia attending the Thalassemia Clinic at Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand were recruited The beta-globin gene mutations and SEA-alpha thalassemia 1 were determined by MS-PCR and Gap-PCR, respectively. The XmnI-Ggamma polymorphism was identified by RFLP analysis. Odds ratio was calculated to evaluate the associations of these three genetic factors and clinical symptoms.
  
  
  RESULTS
  Eight beta-globin gene mutations (both beta0 and beta+) were found Twenty-nine point one percent of the patients had at least one XmnI-Ggamma site (XmnI-Ggamma: +) and 4.1% of the patients were heterozygote for the SEA-alpha thalassemia 1. The beta-globin gene mutations showed maximal impact and the XmnI-Ggamma polymorphism had minimal influence on clinical severity in this cohort. The SEA-alpha thalassemia 1 had the least effect on the clinical severity due to its low prevalence in these patients.
  
  
  CONCLUSIONS
  Although these three genetic factors play roles in modifying clinical symptoms of beta-thalassemia, the beta-thalassemia mutations should be considered first, followed respectively by the XmnI-Ggamma polymorphism and the SEA-alpha thalassemia 1, in management and prenatal diagnosis of beta-thalassemia in northern Thailand.
authors.forename: Thanusak
authors.initials: T
authors.lastname: Tatu
authors.forename: Waratip
authors.initials: W
authors.lastname: Sritong
authors.forename: Torpong
authors.initials: T
authors.lastname: Sa-Nguansermsri
mesh_terms: D002675:Child, Preschool; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D006455:Hemoglobins, Abnormal / Q000235:genetics; D006801:Humans; D007223:Infant; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D012720:Severity of Illness Index; D013785:Thailand; D055542:alpha-Globins / Q000235:genetics*; D017085:alpha-Thalassemia / Q000235:genetics*; D055544:beta-Globins / Q000235:genetics*; D017086:beta-Thalassemia / Q000235:genetics*; D055545:gamma-Globins / Q000235:genetics
chemical_list: D006455:Hemoglobins, Abnormal; D055542:alpha-Globins; D055544:beta-Globins; D055545:gamma-Globins