High frequency of beta thalassaemia in a small island population in Melanesia.

Abstract

A study of the causes of anaemia in the south west Pacific archipelago of Vanuatu has identified one island, Maewo, where the carrier rate for .beta. thalassaemia exceeds 20%, one of the highest recorded incidences in the world. Homozygous .beta. thalassaemia is a major cause of infant mortality and a serious drain on health resources on this island. Interactions of .beta. thalassaemia with various forms of .alpha.+ thalassaemia were common in this population. Coexistent .alpha.+ thalassaemia leads to better haemoglobinised and larger red cells than are seen in simple .beta. thalassaemia heterozygotes and screening for the latter can only be reliably carried out by Hb A2 estimation.