Alpha Thalassaemia and extended alpha globin genes in Sri Lanka

作者：Suresh Sasikala; Fisher Christopher; Ayyub Helena; Premawardhena Anuja; Allen Angela; Perera Ashok; Bandara Dayananda; Olivieri Nancy; Weatherall David^*

来源：Blood Cells, Molecules, and Diseases, 2013, 50(2): 93-98.

DOI：10.1016/j.bcmd.2012.10.001

• alpha Thalassaemia
• HbE beta thalassaemia
• Extended alpha gene arrangements
• Ethnic minority

The alpha-globin genes were studied in nine families with unexplained hypochromic anaemia and in 167 patients with HbE beta thalassaemia in Sri Lanka. As well as the common deletion forms of alpha(+) thalassaemia three families from an ethnic minority were found to carry a novel form of alpha(0) thalassaemia, one family carried a previously reported form of alpha(0) thalassaemia, --(THAI), and five families had different forms of non-deletional thalassaemia. The patients with HbE beta thalassaemia who had co-inherited alpha thalassaemia all showed an extremely mild phenotype and reduced levels of HbF and there was a highly significant paucity of alpha(+) thalassaemia in these patients compared with the normal population. Extended a gene arrangements, including alpha alpha alpha, alpha alpha alpha alpha and alpha alpha alpha alpha alpha, occurred at a low frequency and were commoner in the more severe phenotypes of HbE beta thalassaemia. As well as emphasising the ameliorating effect of a thalassaemia on HbE beta thalassaemia the finding of a novel form of alpha(0) thalassaemia in an ethnic minority, together with an unexpected diversity of forms of non-deletion a thalassaemia in Sri Lanka, further emphasises the critical importance of micro-mapping populations for determining the frequency of clinically important forms of the disease.

• 出版日期2013-2