Rare beta-thalassaemia mutations in Asian indians.

Five beta-thalassaemia mutations hitherto undescribed in Asian Indians were identified in beta-thalassaemia carriers originating from the Indian subcontinent by direct sequencing of their beta-globin genes which were amplified by the polymerase chain reaction (PCR). A T-G substitution at IVS 2 position 837, which probably creates an alternative acceptor splice site and a T insertion in codon 88, resulting in a shift in the reading frame with a premature stop codon, are new beta-thalassaemia mutations. The others were framshift codon 5 (-CT), IVS 1 position 110 (G-A) and IVS-1 minus 1 (G-A) which have been described previously in other populations. These results complete the characterization of the beta-thalassaemia mutations in 708 carriers of Asian Indian origin and will enable a comprehensive programme of carrier screening and prenatal diagnosis of beta-thalassaemia in this population.