<原著>ネパールにおけるサラセミアの分子遺伝学的解析

概要

論文の詳細を見る
Thalassemia is a group of hereditary diseases caused by impaired synthesis of specific globin chains. The disease has a high frequency in regions endemic for malaria including the Mediterranean Basin, Africa, Middle East, Southeast Asia and South China. It has been suggested that the high frequency of thalassemia might reflect advantage due to reduced susceptibility to malaria. To evaluate this malaria hypothesis, we analyzed thalassemia mutations in two neighboring populations of Nepal, the Danuwar and the Tamang. The settlements of the former are located below the limit of the malarial zone (1,200 m in altitude), whereas those of the latter are found in the malaria-free uplands. We detected three heterozygotes for the βE mutation generating HbE in the Danuwars. The haplotype analysis of the β-globin gene cluster harboring the βE mutation suggested that the Danuwars and Southeast Asians share the same origin of the βE mutation. We also detected the 3.7 kb deletion type of α-thalassemia with a high gene frequency, 0.63 in the Danuwars, while in the Tamangs the frequency is only 0.05. Haplotype analysis of the α-globin gene cluster showed that the α-thalassemia mutation has four different genetic backgrounds in the Danuwars. These results suggest that the high frequency of α-thalassemia in the Danuwars is due to the adaptation to malaria endemicity rather than a bottle neck effect.
九州大学の論文
2000-02-10