Asperger's syndrome and ligamentous laxity.

Two autistic girls and one autistic man in whom Asperger's syndrome coexists with lifelong ligamentous laxity and muscular incoordination are described. Two had cranial circumferences at or above the 90th percentile as children, two have complex partial epilepsy, one has a colloid cyst of the third ventricle, and one had evidence of Sotos syndrome. Echocardiography was performed in the two girls and both had evidence of increased aortic compliance. It is suggested that all three suffer from a Marfan-like disorder of connective tissue and, more speculatively, that this has led to anomalous development of midline brain structures with consequent social handicaps characteristic of Asperger's syndrome.