Of these chromosomal anomalies, genes known to cause 46,XY DSD were identified for 4 patients (Table 2) including DMRT1, GATA4 and NR0B1. FISH analysis confirmed the heterozygous deletion of the GATA4 gene in patient 2 and a duplication of the NR0B1 gene in patient 3. The gene discussed is NR0B1; the disease is disorder of sexual differentiation.