It is well established that testicular differentiation of the human embryonic 
gonad depends on the action of the Y-chromosomal gene SRY. However, exceptional 
cases such as SRY-negative cases of 46,XX testicular disorder of sexual 
development (DSD), and of 46,XX ovotesticular DSD document that testicular 
tissue can develop in the absence of the SRY gene. These SRY-negative XX sex 
reversal cases are very rare and usually sporadic, but a few familial cases have 
been reported. We present a large, consanguineous family with nine affected 
individuals with phenotypes ranging from 46,XX testicular DSD to 46,XX 
ovotesticular DSD, with predominance of male characteristics. Absence of SRY in 
peripheral blood was documented by fluorescence in situ hybridization (FISH) and 
PCR analysis in all nine affected individuals, and by FISH analysis on gonadal 
sections with testicular tissue in four affected individuals. By quantitative 
PCR, a duplication of the SOX9 gene was excluded. In addition, as linkage 
analysis showed that the nine affected members of the family do not share a 
common SOX9 haplotype, any mutation at the SOX9 locus could be ruled out. 
Together, these findings implicate a mutation at a sex-determining locus other 
than SRY and SOX9 as the cause for the XX sex reversal trait in this family.