49, Xxxxy Syndrome

49,XXXXY syndrome is a type of chromosome abnormality characterized by the presence of 3 extra X chromosomes in males. It is sometimes referred to as a variant of syndrome/resources/1" target="_blank">Klinefelter syndrome, but differs from Klinefelter syndrome in many ways and is more severe. Signs and symptoms of 49,XXXXY syndrome can vary but may include learning difficulties or intellectual disability; low muscle tone; hypogonadism; infertility; delayed growth; distinctive facial features; and a variety of birth defects that may affect the heart, bones, brain and/or kidneys. It is usually not inherited and caused by a random error in cell division. Treatment depends on the features in each person and is often managed by a multidisciplinary team.