Osteoporotic Fractures and 48xxyy Syndrome: Clinical Case

A C T 48,XXYY syndrome is characterized by the presence of extra X and Y chromosomes and clinically by tall stature, dysfunctional testicles associated with infertility and hypogonadism, developmental delay, behaviour disorders and increased risk of congenital malformations. A 46-year-old man was referred due to an osteoporotic fracture of the left hip. He had epilepsy, reflux esophagitis, dyslipidemia, intellectual disability, and a previous osteoporotic fracture of the right hip. He had never been treated with anti-osteoporotic drugs. Physical examination revealed nonspecific dysmorphic features, central obesity, reduced facial hair, gynecomastia, and testicular atrophy. Biochemical evaluation showed vitamin D insufficiency and hypergonadotropic hypogonadism; karyotype study revealed 48,XXYY. He started treatment with zoledronic acid, intramuscular testosterone, oral calcium and vitamin D supplementation. 48,XXYY syndrome, previously considered a variant of Klinefelter syndrome, is now described as a distinct clinical and genetic entity. Hypogonadism predisposes these patients to osteoporosis and fragility fractures.