Defective sexual development in an infant with 46, XY, der(9)t(8;9)(q23.1;p23)mat.

UNLABELLED: We report on a male infant with ambiguous genitalia (scrotal hypospadias, sinus urogenitalis) trisomic for 8q23-ter and monosomic for 9p23-ter, who shared craniofacial and other abnormalities with either phenotype. Gonadal histology was nearly normal for age. Normal endocrinological findings and exclusion of mutations in SRY, androgen receptor and alpha-reductase genes point to supplementary gene(s) located in 9p2305-ter, haplo-insufficiency (by deletion) of which is expected to cause defective male morphogenesis. CONCLUSION: This observation lends further support to the hypothesis that genetic factors are located at 9p23-ter which are involved in normal sex determination.