Alpha-thalassaemia (Hb-Bart's) in Rajasthan (India).

A total of 1,647 cord blood samples (618 of scheduled tribes, 487 of scheduled castes and 542 of general castes) of newborns from the Banswara, Bhilwara, Chittorgarh, Dungarpur, Sirohi and Udaipur districts of the Aravali hilly region of Rajasthan were investigated electrophoretically for evidence of Hb-Bart's (alpha-thalassaemia). Hb-Bart's was encountered in 31 (1.88%) neonates constituting 1.8 to 12.6% of their total haemoglobin. Of these, 24 (1.46%) were of alpha-thalassaemia 1 and 7 (0.42%) of alpha-thalassaemia 2. The incidence of alpha-thalassaemia genes varied from 3.07% in the scheduled tribes, 1.43% in the scheduled castes to 0.77% in the general castes populations giving an overall incidence of 1.88%. Except Hb-Bart's allele, no other mutant haemoglobins were observed.