XX male syndrome is a condition where an individual, who has both testes but no sperm production (azoospermia), exhibits male characteristics despite having an XX chromosomal pattern. Newborns with this syndrome might be identified due to hypospadias, where the urethral opening is not located at the tip of the penis, or cryptorchidism, which is characterized by undescended testes. However, many with the syndrome have a normal penis and descended testes, and often only seek medical advice after puberty, possibly due to smaller testes, gynecomastia (breast development in a male), or infertility from azoospermia. In some cases, individuals possess the SRY gene, typically found on the Y chromosome and responsible for male development. This can occur due to an unusual exchange between the X and Y chromosomes, resulting in the SRY gene being present on the X chromosome, leading to infertility. Alternatively, the SRY gene might be translocated to an autosome, a non-sex chromosome. This X/autosome translocation can be a new mutation or inherited from a parent.The XX male syndrome is also known as de la Chapelle syndrome, named after Albert de la Chapelle, a Finnish physician who first identified it.
