Cystic fibrosis; hint of linkage with F13B

Isolation of a polymorphic genomic clone from chromosome 7. Physical and genetic linkage studies to markers around the cystic fibrosis locus

A peptide prepared from purified factor 13B (F13B) was sequenced, and a single, long oligonucleotide corresponding to its cognate DNA sequence was constructed and used to screen a chromosome 7 specific genomic library. The positive clone isolated, designated pKV13, was only related to F13B at the oligonucleotide region, but has proved to be a valuable chromosome 7 marker. pKV13 maps to 7pter-q22 in hybrid cell lines, and is present in a chromosome-mediated gene transfer (CMGT) cell line that also contains met and other 7q probes. pKV13 defines a common MspI restriction fragment length polymorphism (RFLP), and is genetically linked to two markers on the long arm of chromosome 7, B79a and COLIA2, both themselves linked to the cystic fibrosis locus. Multipoint linkage analysis demonstrates that KV13 maps centromeric to both B79a and COLIA2. pKV13 has been used to demonstrate the existence of rearrangements within CMGT hybrids, and will also prove valuable in multipoint linkage studies of other 7q markers. Finally, pKV13 provides a new polymorphic locus for the characterisation of 7q deletions in myeloid disorders such as myelodysplastic syndrome.

Coagulation factor XIII: genetic linkage studies with F13B

Linkage relations of the F13B gene with 38 marker genes are analyzed, which, along with the data of earlier reports on the same subject, brings the number of comparisons to a total of 49. Practically all the lod scores are totally negative. This will mean that the F13B gene can hardly be located on the chromosomes/chromosome arms 1p, 2p, 4q, 6p, 14p, 15p, 20q, 21p, 22 and also not on longer segments of 3q, 6q, 7q, 9p, 9q, 11q, 13q, 14q, 16p, and 16q.