Presumed homozygous Ehlers-Danlos syndrome type I in a highly inbred kindred.

While studying an extended family of individuals with the Ehlers-Danlos (ED) syndrome type I, we found an affected male who was born to 2 affected consanguineous parents. This man had a more severe condition than that of his other affected relatives. Moreover, all 6 of his children were affected. Taking the pedigree data into account, the conditional probability of homozygosity for the ED gene in that patient was calculated as 97%. Some problems of the clinical and genetic approach to the recognition of the homozygous state in the ED syndrome are discussed using this family as an example.