Estimating the Recombination frequency for the PTC-Kell linkage

Abstract
Two data sets are analyzed for linkage between the PTC and Kell blood group loci. The original report of close linkage for these loci was that of Conneally et al. (1976), where the maximum likelihood estimate of Θ was 0.05. These two new data sets give a combined maximum likelihood estimate of \(\hat \Theta\) m=f =0.28. Estimating the recombination frequency for the sexes separately gave \(\hat \Theta\) m =0.29, \(\hat \Theta\) f =0.23. The combined maximum likelihood estimate over all published data sets including this report is \(\hat \Theta\) m=f =0.14, \(\hat {\rm Z}\)max=8.94. There is statistically significant evidence of heterogeneity among the published studies.