Primers* were developed to detect 10 mutations in the Indian population. The control primers A and B amplify an 861 bp fragment from the 3’ end of the &bgr;-globin gene. Each primer lies on either side of a 619 bp deletion, which is one of the five most common Indian mutations.5 Therefore, they directly detect this thalassemia mutation by amplifying a characteristic fragment of 242 bp. The other four mutations, which with the 619 bp deletion comprise 90% of Indian &bgr;-thalassaemia, are intervening sequence nucleotide number 5 (IVSI nt5) (G to C), frameshift codon (Fr) 8-9
(+ G), IVSI ntl (G to T), and Fr 41-42 (- CTTT). DNA samples were screened for these mutations using four separate reactions, each containing the two control primers, the common primer C (the primer coupled to either the normal or mutant ARMS primer), and one of the mutant ARMS primers for each of the four mutations. After amplification and electrophoresis, the presence of an amplified band in addition to the control band of 861 bp in one of the reactions signified a particular &bgr;-thalassaemia mutation. If a band of 242 bp was observed in all four of the tracks, the mutation present was the 619 bp deletion gene. If no band apart from the 861 bp control band was observed in all four reactions, it could be concluded that none of the five common mutations was present, and the DNA sample was screened in a similar fashion for the five less frequent Indian mutations.