Open AccessA three-allele restriction-fragment-length polymorphism at the hypoxanthine phosphoribosyltransferase locus in man.
Author(s) -
Robert L. Nussbaum,
W E Crowder,
William L. Nyhan,
C. Thomas Caskey
Publication year - 1983
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.80.13.4035
Subject(s) - biology , genetics , microbiology and biotechnology , locus (genetics) , restriction fragment length polymorphism , allele , restriction enzyme , loss of heterozygosity , hypoxanthine guanine phosphoribosyltransferase , population , gene , genotype , demography , sociology , mutant
Using cloned cDNA sequences of murine and human hypoxanthine phosphoribosyltransferase (HPRT: IMP: pyrophosphate phosphoribosyltransferase, EC 2.4.2.8), we have identified and characterized a three-allele restriction-fragment-length polymorphism for the restriction endonuclease BamHI at the human HPRT locus. The alleles are expressed phenotypically on Southern blots as three distinct pairs of fragments that hybridize to HPRT cDNA: (i) a 22-kilobase (kb)/25-kb pair, (ii) a 12-kb/25-kb pair, and (iii) a 22-kb/18-kb pair. In addition to fragments from the HPRT locus, sequences recognized by both HPRT cDNA probes are also present on at least two autosomes in the human genome. Allele frequencies in an unselected Caucasian population are 0.77 for the 22-kb/25-kb allele. 0.16 for the 12-kb/25-kb allele, and 0.07 for the 22-kb/18-kb allele, resulting in an average heterozygosity of 38% in females in this population. This polymorphism should facilitate gene mapping by linkage in this region of the human X chromosome.