PREVALENCE OF SICKLE CELLS IN IRULA, KURUMBA, PANIYA AND MULLUKURUMBATRIBES OF NILGIRIS (TAMIL-NADU, INDIA)

A total of 1377 tribals, comprising Irulas (536), Paniyas (196), Kurum bas (87), Mullukrurumbas (156) and Soligas (402), living in the Nilgir is, Tamil Nadu, India were studied for sickle cell trait between 1981- 85. Patients attending various tribal clinics at Arayure, Kozhikarai, Kothagiri and Biligiri Rengan hills for various ailments were screened at random by solubility test and by acetate paper electrophoresis, if required. HbAS carrier frequency was 30-37.8 per cent in all the trib als studied except Kurumbas (19.5%). The frequency of carriers were mo re (37.8%) on the western part of Nilgiris (Nedungode, Kappala acid ad joining regions) than the eastern part (30%). Further, the prevalence of carriers was higher (47-49%) in the 10-19 yr age group amongst Pani ,yas and Mullukurumbas living in the western part of Nilgiris. An epis odic, epidemic of malaria so rampant during the early part of this cen tury in the western parts of Nilgiris might have eliminated many child ren with HbAA and hence the higher frequency of HbAS in this particula r age group.