Borjeson-Forssman-Lehmann syndrome (BFLS) is a genetic condition characterized by intellectual disability, obesity, seizures, hypogonadism, developmental delay and distinctive facial features. These symptoms are variable, even among members of the same family. BFLS is caused by mutations in the PHF6 gene on the X chromosome. This mutation is usually transmitted as an X-linked recessive trait, which means the disorder is fully expressed predominantly in males.