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B J Wainwright

Publications and source records attributed to B J Wainwright.

43 records · Page 3Linked to original sources

Linkage of DNA probe B79a (D7S13) to cystic fibrosis.

We have conducted, in 64 affected families, a study of linkage between the anonymous DNA segment pB79a (D7S13) and the locus for cystic fibrosis (CF) on chromosome 7q. The maximum lod score was 12.60 at theta = .08 (confidence bounds .045-.135). Although D7S13 is not sufficiently close to CF for routine use in DNA-based prenatal diagnosis, it will be helpful in certain families when other nearby markers are uninformative. D7S13 will also be useful for refining the linkage map of the CF region.

Cystic Fibrosis↗

Isolation of a further anonymous informative DNA sequence from chromosome seven closely linked to cystic fibrosis.

A library prepared from flow-sorted chromosomes was used to isolate single-copy sequences from chromosome seven. One such sequence 7C22 has been shown to be polymorphic for an EcoRI restriction site and to be informative for the study of CF in approximately 35% of matings. The segregation of the 7C22 alleles was followed through nineteen informative families with more than one child affected by cystic fibrosis. We report that the locus for 7C22 is linked to the locus for cystic fibrosis at a recombination fraction of 0.045. This marker will prove useful in improving the accuracy and informativeness of prenatal diagnosis and in constructing a fine genetic map around the cystic fibrosis gene.

Chromosomes, Human, 6-12 and X↗

Microdissection of and microcloning from the short arm of human chromosome 2.

A bank of cloned DNA sequences from the distal half of the short arm of human chromosome 2 was generated by using microdissection and microcloning techniques. DNA was purified from 106 chromosomal fragments, manually dissected from peripheral lymphocytes in metaphase, and cloned into the EcoRI site of lambda gt10. A total of 257 putative recombinants were recovered, of which 41% were found to contain human inserts. The mean insert size was 380 base pairs (median size, 83 base pairs), and fewer than 10% of the clones contained highly repetitive sequences. All single-copy sequences examined were shown to map to the short arm of chromosome 2 by using hybrid panels. This technique provides a rapid method of isolating probes specific to a human subchromosomal region to generate linked markers to genetic diseases for which the chromosomal location is known.

Base Sequence↗

Exclusion of human chromosome 13q34 as the site of the cystic fibrosis mutation.

We have studied a family in which both cystic fibrosis (CF) and an unbalanced translocation between chromosomes 6 and 13 are found. As CF occurs in the child who is effectively monosomic for the translocated part of the long arm of chromosome 13, it was suggested that the locus of the gene mutation causing CF is on chromosome 13q34. The gene for human coagulation factor X is located at 13q34, and we have found a restriction fragment length polymorphism (RFLP) that is revealed by a cloned cDNA coding for this protein. Linkage analysis in eight CF families shows no evidence of cosegregation between CF and the gene for factor X, strongly suggesting that the locus for the defect causing cystic fibrosis is not at 13q34.

Chromosome Mapping↗

Localization of cystic fibrosis locus to human chromosome 7cen-q22.

Cystic fibrosis (CF) is the most common genetic disease in Caucasian populations, with an incidence of 1 in 2,000 live births in the United Kingdom, and a carrier frequency of approximately 1 in 20. The biochemical basis of the disease is not known, although membrane transport phenomena associated with CF have been described recently. Consanguinity studies have shown that the inheritance of CF is consistent with it being a recessive defect caused by a mutation at a single autosomal locus. Eiberg et al. have reported a genetic linkage between the CF locus and a polymorphic locus controlling activity of the serum aryl esterase paraoxonase (PON). The chromosomal location of PON, however, is not known. Linkage to a DNA probe, DOCR1-917, was also recently found at a genetic distance of approximately 15 centimorgans (L.-C. Tsui and H. Donnis-Keller, personal communication), but no chromosomal localization was given. Here we report tight linkage between the CF locus and an anonymous DNA probe, pJ3.11, which has been assigned to chromosome 7cen-q22.

Chromosome Mapping↗