Suresh, S.Fisher, C.Ayyub, H.Premawardhena, A.Allen, A.Perera, A.Bandara, D.Olivieri, N.Weatherall, D.2021-06-262021-06-262013Blood cells, Molecules & Diseases.2013;50(2):93-81079-9796 (Print)1096-0961 (Electronic)http://repository.kln.ac.lk/handle/123456789/22864Indexed in MEDLINE; ScopusThe α-globin genes were studied in nine families with unexplained hypochromic anaemia and in 167 patients with HbE β thalassaemia in Sri Lanka. As well as the common deletion forms of α(+) thalassaemia three families from an ethnic minority were found to carry a novel form of α(0) thalassaemia, one family carried a previously reported form of α(0) thalassaemia, --(THAI), and five families had different forms of non-deletional thalassaemia. The patients with HbE β thalassaemia who had co-inherited α thalassaemia all showed an extremely mild phenotype and reduced levels of HbF and there was a highly significant paucity of α(+) thalassaemia in these patients compared with the normal population. Extended α gene arrangements, including ααα, αααα and ααααα, occurred at a low frequency and were commoner in the more severe phenotypes of HbE β thalassaemia. As well as emphasising the ameliorating effect of α thalassaemia on HbE β thalassaemia the finding of a novel form of α(0) thalassaemia in an ethnic minority, together with an unexpected diversity of forms of non-deletion α thalassaemia in Sri Lanka, further emphasises the critical importance of micro-mapping populations for determining the frequency of clinically important forms of the disease.en-USalpha-Globins-geneticsalpha-Thalassemia-epidemiologyalpha-Thalassemia-geneticsSri Lanka-epidemiologyHemoglobin E-geneticsThalassemiaArticle