Haemoglobinopathies in east Asia

Natural selection and population diversity

It is an observed fact that human populations differ in genetic composition. Some of the inherited diversity is due to combined effects of many genes. Although it would be interesting to know the magnitude and nature of the genetic contribution to some characters under polygenic control, such as intelligence or physique, environmental effects may be so great that no genetic analysis is possible—as Thoday has pointed out earlier in this symposium. With other polygenic characters, such as skin colour, the genetic component is more obvious but still difficult to analyse precisely. The number of genes involved, their frequency and dominance have not been established. This is one of the reasons why selective effects on such characters are not readily measured, although they probably exist.

Hemoglobin variants in Koreans: hemoglobin G Taegu

Hemoglobin G Taegu, an electrophoretically slow hemoglobin with a structural anomaly believed to be in the beta-T-3 section of the beta chain, was the only variant found among 6700 normal Koreans. Four subjects, 0.06 percent, had the G-hemoglobin variant in addition to normal hemoglobin A. Hemoglobin E, known in numerous groups from Southeast Asia and the variant most frequently seen in Chinese subjects, was not found among the Koreans we tested.