DNA markers near the cystic fibrosis locus: further analysis of the British population.

Genetic analysis of the CF locus in the British Caucasian population has been extended using six DNA probes detecting nine polymorphic loci. Data are presented on (1) diagnostic usefulness of probes, and (2) allele frequencies for each probe in this population. For the probes pXV2C and KM19 (those closest to the CF locus) allele frequencies are further subdivided into male and female derived chromosomes 7. The allele frequencies for both probes on non-CF bearing chromosomes 7, but not on CF carrying chromosomes 7, are substantially different in males and females. Combined haplotypes for pXV2C and KM19 show that, as has been observed in other northern European populations, almost 90% of CF chromosomes in this population carry the pXV2C/KM19, 1/2 (2.1 kb/6.6 kb) haplo-type.