Neonatal McCune–Albright syndrome with systemic involvement: a case report

Rita Lourenço, Patrícia Dias, Raquel Gouveia, Ana Berta Sousa, Graça Oliveira

McCune-Albright syndrome is a rare sporadic disease characterized by fibrous bone dysplasia, café-au-lait skin spots and variable hyperfunctional endocrinopathies. McCune-Albright syndrome is caused by somatic postzygotic activating mutations in the GNAS gene that produce a broad spectrum of effects. We report a case of McCune-Albright syndrome with multi-organ manifestations in the neonatal period. A newborn preterm black girl was referred to our Neonatal Intensive Care Unit at the age of 17 days for suspected extrahepatic cholestasis. On clinical examination she presented failure to thrive, jaundice, hypertension, marked hypotonia and café-au-lait spots on her back and lower limbs. An abdominal ultrasound excluded extrahepatic causes of cholestasis but revealed bilateral serpiginous adrenal hyperplasia. These clinical findings suggested a diagnosis of McCune-Albright syndrome with multi-organ involvement. Laboratory data confirmed adrenocorticotropic hormone-independent Cushing's syndrome, hyperthyroidism, cholestasis and elevated transaminases. Ventricular hypertrophy was demonstrated by echocardiography. The baby girl underwent medical treatment of Cushing's syndrome with metyrapone which was followed by a rapid recovery. A mosaic activating GNAS gene mutation was found on DNA extracted from a buccal swab sample. However, she died at 4 months due to a respiratory infection. In the neonatal period the diagnosis of McCune-Albright syndrome depends on having a high index of suspicion and café-au-lait spots may be the clue for the diagnosis.