Pseudoachondroplasia with cerebral and renal cysts.

Pseudoachondroplasia (PSACH) is a spondylo-epi-metaphyseal dysplasia characterised by disproportionate short stature, generalised ligamentous laxity and precocious osteoarthritis. Autosomal dominant inheritance has been demonstrated in many families. The present case was normal at birth. By 3 years of age his height has fallen below the 5th percentile. At 6 1/2 years of age he was 99 cm tall (-3.5 SD), and he had bowing of the lower extremities and some limitations of movements at the elbows and knees. Radiographs showed features of PSACH. Kypho-scoliosis appeared later on with anterior beaking of the vertebrae. Cerebral CT scan showed a very large frontal cyst communicating with the IIIrd ventricle. RMI confirmed the frontal cyst and showed dilatation of the IIIrd ventricle and of the occipital horns of the lateral ventricles, and a right frontal parietal hemispheric atrophy. At 26 years of age he complained of pain in the knees, swallowing difficulties, and vertigo. Renal ultrasonographic examination showed a large cortical cyst of the right kidney and smaller cysts in both kidney.