The Authors report a case of mixed gonadal dysgenesis (DGM), with a mosaic karyotype consisting of two cell lines, one with 45 chromosomes and monosomic X (50%), the other with 46 chromosomes and one Y dicentric chromosome (50%). The patient presents a male phenotype, hypospadias (3rd degree), left cryptorchidism, hypotrophic right testis, short stature and a gonadal asymmetry.