Craniofacial and brain abnormalities in Laron syndrome (primary growth hormone insensitivity)

To investigate abnormalities in the craniofacial structures and in the brain in patients with Laron syndrome.

Eleven patients with classical Laron syndrome, nine untreated adults aged 36-68 years and two children aged 4 and 9 years (the latter treated by IGF-I), were studied.

Magnetic resonance images of the brain were obtained in all the patients. One patient also underwent computed tomography. The maximal diameter of the maxillary and frontal sinuses was measured and compared with reference values, the size of the sphenoid sinus was evaluated in relation to the sella, and the mastoids were evaluated qualitatively (small or normal). The brain was evaluated for congenital anomalies and parenchymal lesions.

In the adult untreated patients, the paranasal sinuses and mastoids were small; in six patients, the bone marrow in the base of the skull was not mature. The diploe of the calvaria was thin. On computed tomography in one adult patient, the sutures were still open. A minimal or mild degree of diffuse brain parenchymal loss was seen in ten patients. One patient demonstrated a lacunar infarct and another periventricular high signals on T2-weighted images. Two patients had cerebellar atrophy.

The present study has demonstrated the important role IGF-I plays in the development of the brain and bony structures of the cranium.