DELETIONS OF DISTAL 9P ASSOCIATED WITH 46,XY MALE TO FEMALE SEX REVERSAL - DEFINITION OF THE BREAKPOINTS AT 9P23.3-P24.1

Monosomy of distal 9p is associated in rare cases with abnormalities o f testicular determination, which can lead to male to female sex rever sal in a 46,XY genetic background. We present two 46,XY individuals pa rtially monosomic for 9p who were raised as females. Definition of the breakpoints using somatic cell hybrids containing only the rearranged chromosome 9 indicated that in the first patient the breakpoint was l ocated between markers D9S256 and D9S144 and in the second patient, th e breakpoint was distal to the marker D9S144. In both cases this corre sponds to the cytogenetic position 9p23.3-p24.1. Analysis of highly po lymorphic microsatellite markers demonstrated a paternal origin of the rearranged chromosome 9 in both patients. These studies define the mi nimum region associated with male to female sex reversal as 9p24.1-pte r. (C) 1997 Academic Press.