Infantile systemic hyalinosis in identical twins.

Infantile systemic hyalinosis (ISH) is a rare disorder belonging to the heterogeneous group of genetic fibromatoses. It is a rare, progressive, fatal autosomal recessive condition characterized by widespread deposition of hyaline material in many tissues caused by mutations in the anthrax toxin receptor 2 gene - ANTXR2. It presents hyperpigmented skin over bony prominences.