Detection of Lesch‐Nyhan Syndrome Carriers: Analysis of hair roots for HPRT by agarose gel electrophoresis and autoradiography

Abstract

Flat agarose gel electrophoresis and autoradiography were used to analyze HPRT [hypoxanthine phosphoribosyl transferase EC 2.4.2.8) and APRT [adenine phosphoribosyltransferase] activity in individual hair roots collected from the scalps of females to determine the presence of HPRT-deficient cells. Autoradiographs of hair-root lysates of normal homozygous females contained 2 well-separated dark zones representing HPRT and APRT activities. Some hair roots from carriers of HPRT deficiency contained 2 zones of activity with the same relative proportion of APRT and HPRT as hair roots of normal homozygotes, while others contained decreased amounts of HPRT activity. These hair roots consisted of HPRT+ and HPRT- cells. Some hair roots from heterozygous carriers contained APRT, but no HPRT activity. Such hair roots consisted of HPRT- cells only. [This method will be of use for genetic counseling].