Hypoxanthine-Guanine Phosphoribosyltransferase and Deutan Colour Blindness: The Relative Positions of Their Loci on the X-Chromosome
Many studies of X-linked characteristics have suggested that the loci for colour blindness, glucose-6-phosphate dehydrogenase (G-6 PD) and antihaemophilic globulin (AHG) form a fairly close-linked group on the X chromosome, all of which are moderately distant from the locus for Xg antigen (1). Little information is available however concerning the site of the locus for hypoxanthineguanine phosphoribosyltransferase (HGPRTase) on the X chromosome. This locus has been regarded as being not close to that for G-6 PD because two cross-overs were observed in a single family (2) and no linkage was detected between the HGPRTase locus and Xg antigen (3). Thus, when a patient with a moderate deficiency of HGPRTase, who presented with uric acid calculi and severe gouty arthritis without any neurological signs was found also to be colour blind, members of his family were studied to see if useful information could be obtained concerning the relative positions of the loci for HGPRTase and colour blindness.
KeywordsRecombination Fraction Purine Base Colour Blindness Erythrocyte Lysate Double Heterozygote
Unable to display preview. Download preview PDF.
- 1.RACE, R.R. and SANGER, R. (1968). “Blood Groups in Man” 5th Edition. Oxford: Blackwell pp. 537–556.Google Scholar
- 4.EMERSON, B.T., THOMPSON, C.J. and WALLACE, D.C. (1972). Partial deficiency of hypoxanthine-guanine phosphoribosyltransferase: Intermediate enzyme deficiency in heterozygote red cells. Ann. Intern. Med. 76: 285–287.Google Scholar
- 6.RENWICK, J.H. and BOLLING (1967). A program-complex for encoding, analysing card storing human linkage data in Crow, J.F. and Neele, J.V. (Eds.). Proceedings of the Third International Congress of Human Genetics. Baltimore, Johns Hopkins, pp. 497–506.Google Scholar