Börjeson-Forssman-Lehmann syndrome

Börjeson-Forssman-Lehmann syndrome is a rare genetic disease that causes intellectual disability, obesity and growth defects. It is an X-linked recessive disorder caused by mutations in PHF6, a gene that encodes a zinc finger protein involved in cell growth, and it occurs mainly in people with XY chromosomes because they carry only one copy of the X chromosome. Babies are born at a normal weight but have low muscle tone and difficulty feeding, and moderate to severe intellectual disability becomes evident as development proceeds. Characteristic features include ptosis, large ears, short stature in about half of those affected, gynecomastia, short toes and tapered fingers, with hypogonadism and cryptorchidism common in boys. Diagnosis is confirmed by genetic testing. There is no cure, and symptoms are managed with surgery and medication. The syndrome was described in 1962 by the physicians for whom it is named, and fewer than one hundred cases have been reported in the literature.