Fukami et al. (2006) performed direct sequencing of the coding exons 3-6 of the CXORF6 (MAMLD1) gene and their flanking splice sites in 166 individuals with various types of 46,XY disorders of sex development. They identified 3 nonsense ... Fukami et al. (2006) performed direct sequencing of the coding exons 3-6 of the CXORF6 (MAMLD1) gene and their flanking splice sites in 166 individuals with various types of 46,XY disorders of sex development. They identified 3 nonsense mutations (300120.0001-300120.0003) in 4 Japanese individuals with penoscrotal hypospadias as the conspicuous phenotype. The mutations were predicted to cause nonsense-mediated mRNA decay because of their positions. Consistent with this, RT-PCR for leukocytes indicated markedly reduced transcripts. All affected individuals had seemingly normal pituitary-gonadal serum hormone levels.