Hb Q-Thailand [alpha 74(EF3)Asp-->His]: gene organization, molecular structure, and DNA diagnosis.
Hb Q-Thailand [alpha 74(EF3)Asp-->His] is often found in Thailand, China, and other Southeast Asian countries. The alpha-Q-Thailand gene is strongly linked to an alpha gene deletion and has important implications in the identification and diagnosis of hemoglobinopathies and thalassemias. The alpha-Q-Thailand mutation was previously mapped to the alpha 1 gene in a study of Chinese patients. In this paper, a Thai patient with Hb Q-Thailand/Hb H disease and his mother were studied at the DNA level, and the gene organization of Hb Q-Thailand in the Thai patient was found to be the same as that of Chinese patients (i.e. the Hb Q-Thailand gene is located on the alpha 1 gene of chromosome #16, while the -4.2 kb or leftward deletion involves the alpha 2 gene). Also, the GAC-->CAC mutation proposed at codon 74, has been confirmed by DNA sequencing and a simple and accurate method for diagnosis of the Hb Q-Thailand variant has been developed based on restriction enzyme analysis. Since the GAC-->CAC mutation generates new cutting sites for both restriction enzymes Apa LI and Hgi AI, polymerase chain reaction amplification of a specific region around codon 74, followed by digestion with these enzymes and agarose gel electrophoresis of the digested products, permits rapid and accurate identification of Hb Q-Thailand.
Zeng
F Y
FY
Laboratory of Chemical Biology, National Institute of Diabetes, Digestive and Kidney Diseases National Institutes of Health, Bethesda, MD 20892.
Fucharoen
S
S
Huang
S Z
SZ
Rodgers
G P
GP
D001483:Base Sequence; D004247:DNA / Q000235:genetics*; D005260:Female; D006455:Hemoglobins, Abnormal / Q000235:genetics*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009154:Mutation / Q000235:genetics; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping; D017085:alpha-Thalassemia / Q000175:diagnosis* / Q000235:genetics
D006455:Hemoglobins, Abnormal; C049214:hemoglobin Q Thailand; D004247:DNA