Molecular epidemiology investigation of beta-thalassemia in Zhongshan City, Guangdong Province, People's Republic of China.

Beta-THAlassemia (beta-thal) is one of the most common genetic diseases in southern China. In order to obtain detailed epidemiology data to be used for primary prevention programs, we have analyzed 2,055 independent subjects living in Zhongshan City, Guangdong Province, People's Republic of China (P.R. China), by using hematological biochemical screening and DNA technology. The results indicate a higher prevalence (3.07%) of beta-thal and coinheritance of alpha- and beta-thal (0.49%) than previously reported for Guandong Province. Ten beta-thal mutations were found in 63 independent chromosomes. The four most common mutations [codons 41/42 (-TCTT), IVS-II-654 (C>T), -28 (A>G), codon 17 (A>T)] accounted for 90.46% of the total. The uncommon mutations profile was different from that of other cities in Guangdong Province and the rare mutation IVS-II-2 (-T), once reported in Hong Kong, was also detected. This study will contribute to the development of prevention strategies in the region, allowing better genetic counseling and prenatal diagnosis of beta-thal.