This study analyses distribution patterns of the delta F508 mutation of the cystic fibrosis transmembrane conductance regulator gene (CFTR) gene and the cystic fibrosis (CF)-linked marker loci MET, D7S23, D7S399, and D7S8 in a sample of 167 (116 complete) CF families from Bohemia and Moravia (Czechoslovakia).
Our previous linkage analysis suggested that the DNA segment D7S122 is located between MET and D7S8, the two genetic markers that are thought to flank the cystic fibrosis locus (CF).
Data for XV2c and MET markers in 16 American black patients and their families revealed a different haplotype distribution and LD pattern with the CF locus.
In a 1:4 risk family, the usefulness of probes at the D7S23 locus for prenatal diagnosis of cystic fibrosis is discussed by comparison with probes at the MET, D7S8, and D7S18 loci that did not allow accuracy in this family.
We have demonstrated the assignments of two gene loci (COLIA2, MET) and two noncoding DNA markers (D7S13, D7S8) to owl monkey chromosome 14 (K-VI) by hybridizing DNA probes from the cystic fibrosis (CF) region of human chromosome 7q21-32 to panels of rodent-owl monkey somatic cell hybrids.
The frequency distribution of CF haplotypes in the Hutterite sample differs notably from those of larger agglomerates of family data from collaborative studies, with respect to D7S8, MET haplotypes, and D7S23 haplotypes.
Together with the previously identified markers, MET, D7S8, D7S13 and D7S16, these new markers should provide a fine genetic and physical map for the chromosomal region surrounding CF.
These data and in situ chromosomal hybridization analysis would indicate that MET and, therefore, the cystic fibrosis locus are located at bands q31-q32 on human chromosome 7.
Preliminary large-scale restriction mapping of the fragment showed that the NotI polymorphic site is 200-370 kb distant from the MET locus; thus it defines a new polymorphic locus in the CF region.
There are significant allelic associations between CF, MET, D7S8 and D7S16; these allelic associations affect the risk of random individuals to be carriers of CF.
A collaborative study involving seven research groups provided an opportunity to investigate the linkage relationships between cystic fibrosis and two DNA marker loci, MET and pJ3.11 (D7S8), on an extended sample of 211 tested families.