Distribution and ethnic variation of â-thalassemia mutations in Nepal

This is the first study characterizing spectrum of beta-thalassemia mutations in Nepalese population. Mutations were analyzed in 22 patients using 10 sets of allele-specific primers. Five of the mutations, namely F.S 41/42 (--TCTT), IVS1 nt5 (G-->C), IVS1 nt1 (G-->T), 619 bp deletion and F.S 8/9 (+G), were found to constitute 87.82% of total alleles studied. F.S 41/42 (--TCTT) was the commonest mutation. -88 (C-->T), Codon 16 (--C) and Codon 15 (G-->A), had a combined frequency of 12.18%. Distribution of mutations causing beta-thalassemia in different ethnic Nepalese groups was analyzed. The mutational profile in Nepal share several similarities with that from the two neighboring countries, India and China. Detection of more than one mutation in three cases of thalassemia trait raises the likelihood of existence of multiple mutations in cis in Nepalese thalassemic carriers. Such possibility has to be carefully considered while developing prenatal screening program for Nepalese population.