Nonrandom selection of hair follicles in HPRT heterozygosity.

Abstract

The gene for hypoxanthine phosphoribosyltransferase (HPRT) has been mapped to the X chromosome, and HPRT-deficiency syndromes are inherited in an X-linked recessive manner.1 Two populations of cells can be demonstrated in the female heterozygous carriers of these syndromes. While great strides have been made in the detection of point mutations in cDNA, these methods are not yet sufficiently reliable for routine detection of heterozygotes.2 At present, biochemical methods which detect HPRT+ and HPRT− populations of cells are both technically simpler and more reliable. Cultured fibroblasts, lymphocytes, and hair roots have been used for this purpose.1 Of these three, we have found the hair root method to be the least invasive, fastest, and most reliable.3 In the past 15 years we have detected a total of 94 heterozygous carriers of HPRT-deficiency syndromes by this method.