Studies of β-Thalassemia Mutations in Families Living in Three Provinces in Southern China

Abstract
.beta.-Thalassemia is a common disease in Southern China and 10 different mutations or frameshift are responsible for most types of .beta.-thalassemia in this area. We studied 126 chromosomes of 80 .beta.-thalassemia patients from the Guangxi, Guangdong, and Sichuan Provinces using the polymerase chain reaction followed by dot-blot hybridization with specific oligonucleotide probes. The most common mutation in the three provinces is the frameshift at codons 41-42, followed by the A.fwdarw.T mutation at codon 17. The A.fwdarw.G mutation at nt -29 of the promoter is common in Sichuan but not in the other two provinces. Three mutations (T.fwdarw.C at nt -30; G.fwdarw.T at IVS-I-1, and G.fwdarw.C at IVS-I-5) were not observed. These data were used to initiate a prenatal diagnosis program using the same techniques for identification. Eleven fetuses at risk for .beta.-thalassemia have been diagnosed.