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. Characteristic purplish patches develop over the medial and lateral malleoli of the ankles, the metacarpophalangeal joints, spine and elbows, with progressive joint contractures, osteopenia, skin abnormalities and chronic severe pain. The present case reports the occurrence of infantile systemic hyalinosis in twin brothers five months of age who had come for early intervention for joint contractures representing characteristic brownish patches over bony prominences. ISH cases reported until this date have been less than 20 and the present case is unique in nature since this is the first time ISH is reported in twins globally and the symptoms have been identified at an early age.