Endocrine abnormalities in cardiofaciocutaneous syndrome: a case of precocious puberty, hyperprolactinemia and diabetes insipidus.

A 7-year-8-month-old boy with cardiofaciocutaneous syndrome caused by the D638E mutation of the B-Raf proto-oncogene (BRAF) presented with new-onset seizures. He was incidentally found to have advanced Tanner staging on physical examination. Hormonal testing revealed pubertal levels of gonadotropins and sex steroid hormones. On brain imaging, a lack of visualisation of the posterior pituitary bright spot was observed, in addition to mild thinning of the corpus callosum and the lateral gyri of the cerebellar hemispheres. A diagnosis of idiopathic central precocious puberty was made and the patient was started on leuprolide depot treatment. Pituitary hormone testing revealed hyperprolactinemia for which the patient did not receive treatment as he was asymptomatic. During a subsequent hospital admission for seizures, the patient was diagnosed with transient central diabetes insipidus for which he required treatment with a desmopressin infusion. © BMJ Publishing Group Limited 2019. No commercial re-use. See rights and permissions. Published by BMJ.