Rare β-thalassemia mutations in Asian Indians

Among 365 carriers of β-thalassemia, 13 subjects remained uncharacterized after ARMS analysis. Among these 13 individuals, 8 mutations were identified by direct sequencing of the PCR-amplified product, which have not been described in Asian Indians earlier. These included (1) T-C substitution at IVS II position 591, a new β-thalassemia mutation which probably creates an alternative donor splice site in antisense strand; (2) the mutations CoD4 (T-A), CoD5 (C-T), CoD6 (G-T) at cis location; (3) CoD13 (C-T), CoD26 (G-A), CoD 27/28(-C) at cis location; (4) CoD 8 (A-G); (5) CoD30 (G-C); (6) CoD5 (-CT); (7) IVSI-1 (G-A); and (8) FS47/48 (+ATCT). The latter four have been described in other populations but are identified in Asian Indians for the first time. This completes the characterization of β-thalassemia mutations in 365 carriers of Asian Indian origin, enabling us to provide a comprehensive prenatal diagnosis of β-thalassemia in our population