Further clinical delineation of the Börjeson-Forssman-Lehmann syndrome in patients with PHF6 mutations.

Börjeson-Forssman-Lehmann syndrome is an X-linked condition caused by PHF6 mutations. The classical description of males with this disorder includes severe intellectual disability with epilepsy, microcephaly, short stature, obesity, hypogonadism, and gynecomastia. We present three males with PHF6 mutations whose features included deep-set eyes, large ears, coarse face, tapering fingers, and truncal obesity. Unlike the original description of the syndrome; however, the males described herein had varying degrees of intellectual disability and hypogonadism, were of normal to tall stature, had normal to large head sizes, and did not have seizures. This departure from the usual clinical description of Börjeson-Forssman-Lehmann syndrome is consistent with recent reports of males with mutations in PHF6. In addition, we describe the phenotype and X-inactivation pattern in two females heterozygous for PHF6 mutations, both of whom have mild features of the syndrome.