Testing for heterogeneity of recombination fraction values in Human Genetics

SUMMARY A method is described for the detection of heterogeneity of recombination fraction values in human data. It uses a comparison of likelihood values. It is applied to the data on elliptocytosis and rhesus previously considered by Morton (1956), together with some new data reported by Bannerman & Renwick (1962). Morton's conclusion that there exists heterogeneity is supported by the new test. The data appear to be best explained by the hypothesis that the families divide themselves into two groups. In the first group, which amounts to something between 20 and 90 % of the whole, the locus for elliptocytosis is closely linked with that for rhesus, the recombination fraction being between 0.01 and 0.1. In the remaining families the two loci are unlinked.