title: Prevalence of α-thalassaemia genotypes in pregnant women in northern Thailand.
abstract: OBJECTIVE
  Alpha-thalassaemias are genetic disorders with high prevalence in northern Thailand. However, common genotypes and current data on the prevalence of α-thalassaemias have not been reported in this region. Therefore, the objective of the present study was to determine the prevalence of α-thalassaemia genotypes in pregnant women in northern Thailand.
  
  
  METHODS
  Genomic DNA was extracted from blood samples of pregnant women who came to Maharaj Nakorn Chiang Mai University Hospital during July 2009 to 2010. The common deletion and point mutation genotypes of α-thalassaemia were evaluated by gap- polymerase chain reaction (PCR) and PCR with restriction fragment length polymorphism (RFLP).
  
  
  RESULTS
  Genotypes of 638 pregnant women were: 409 samples (64.11%) being normal subjects (αα/αα) and 229 samples (35.89%) with α-thalassaemias. these 229 samples could be classified into deletional HbH disease (--SEA/-α3.7) for 18 samples (2.82%); heterozygous α0-thalassaemia --SEA type (--SEA/αα)) for 78 (12.23%); heterozygous α+-thalassaemia - α3.7 type (-α3.7/αα) for 99 (15.52%); homozygous α+-thalassaemia - α3.7 type (-α3.7/- α3.7) for five (0.78%); heterozygous α+-thalassaemia - α4.2 type (-α4.2/αα) for two (0.31%); and heterozygous HbCS (αCSα/αα) for 27 (4.23%) cases.
  
  
  CONCLUSIONS
  The prevalence of α-thalassaemias in pregnant women in northern Thailand was high. This finding supports the implementation of the prevention and control of this common genetic disorder by screening for α-thalassaemia genotypes.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Somphon
authors.initials: S
authors.lastname: Pharephan
authors.affiliation: Department of Obstetrics & Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Pannee
authors.initials: P
authors.lastname: Sirivatanapa
authors.affiliation: Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Sanit
authors.initials: S
authors.lastname: Makonkawkeyoon
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Wirote
authors.initials: W
authors.lastname: Tuntiwechapikul
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Luksana
authors.initials: L
authors.lastname: Makonkawkeyoon
mesh_terms: D000328:Adult; D005260:Female; D005838:Genotype; D006447:Hemoglobin H / Q000235:genetics*; D006455:Hemoglobins, Abnormal / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D017354:Point Mutation / Q000235:genetics; D011247:Pregnancy; D017384:Sequence Deletion / Q000235:genetics; D013785:Thailand / Q000453:epidemiology; D017085:alpha-Thalassemia / Q000097:blood / Q000453:epidemiology / Q000235:genetics*
chemical_list: D006455:Hemoglobins, Abnormal; D006447:Hemoglobin H; C035541:Hemoglobin Constant Spring