Molecular analysis of mutations in the hprt gene in circulating lymphocytes from normal and DNA-repair-deficient donors.
Circulating lymphocytes from patients with the DNA-repair-deficient disorders, xeroderma pigmentosum (XP) and ataxia telangiectasia (A-T) have elevated frequencies of mutants at the hypoxanthine-guanine phosphoribosyltransferase (hprt) locus. We have analysed the DNA sequence of the hprt gene in mutants from normal donors, and compared them with mutants from XP and A-T individuals. In normal donors we found a range of mutations including principally transitions (40%), transversions (32%) and small deletions (20%). In an excision-deficient XP donor from complementation group C the mutation spectrum was similar to that from normal donors, whereas in an XP variant there was a significantly higher frequency (44%) of small deletions. In the two A-T donors, there was a high frequency of large deletions (22 and 75%) compared with only 4% in normal donors.
Steingrimsdottir
H
H
MRC Cell Mutation Unit, University of Sussex, Falmer, Brighton, UK.
Rowley
G
G
Waugh
A
A
Beare
D
D
Ceccherini
I
I
Cole
J
J
Lehmann
A R
AR
D000328:Adult; D000367:Age Factors; D000368:Aged; D001260:Ataxia Telangiectasia / Q000201:enzymology / Q000235:genetics*; D002648:Child; D004252:DNA Mutational Analysis; D004260:DNA Repair; D015329:Gene Rearrangement, T-Lymphocyte; D005816:Genetic Complementation Test; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics*; D008214:Lymphocytes / Q000201:enzymology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011948:Receptors, Antigen, T-Cell / Q000235:genetics; D017384:Sequence Deletion; D014983:Xeroderma Pigmentosum / Q000201:enzymology / Q000235:genetics*
D011948:Receptors, Antigen, T-Cell; D007041:Hypoxanthine Phosphoribosyltransferase