Familial aggregation of a "new" connective-tissue disorder: a nosologic problem.

Three brothers are described who had a severe connective-tissue disorder and died in infancy. They were the offspring of a consanguineous union and members of a kindred in which other paternal relatives were found to have the benign hypermobile form of Ehlers-Danios syndrome. The findings in the three brothers were not clearly representative of any known connective-tissue disorder. The authors feel that the brothers' phenotype is best explained as a result of genetic interaction between the Ehlers-Danios gene and another single unspecified gene in double dose.