Phenotype i associated with congenital cataract in Japanese

A Japanese family with two siblings of phenotype i is presented. Both had a past history of surgical treatment for congenital cataract. In Japan, 18 individuals of phenotype i, including our case, have been found in ten unrelated families. Seventeen of them had congenital cataract. Cataract was not found in any of the 45 phenotype I members in these families. It is briefly discussed why these two linked and quite rare genes were found in combination only in Japanese persons.