Infantile systemic hyalinosis in an Iranian family with a mutation in the CMG2/ANTXR2 gene

Summary Infantile systemic hyalinosis (ISH) is an extremely rare genodermatosis, characterized by thickened skin, joint contractures and subcutaneous nodules. ISH is caused by mutations in the CMG2 gene, which encodes a protein of unknown function. In this report, we describe a patient with ISH, who was a twin born to a consanguineous Iranian couple, and who demonstrated unusual skin findings in addition to the characteristic features of ISH. Mutation analysis disclosed a homozygous deletion mutation, c.1074delT in CMG2, resulting in a frameshift and premature termination codon 50 amino acids downstream of the deletion. This information adds to the recurring nature of this mutation in ISH, with implications for genetic counselling in extended families with a history of this disease.