Hyaline Fibromatosis Syndrome: A Novel Mutation and Recurrent Founder Mutation in the CMG2/ ANTXR2 Gene

خلاصه: Hyaline Fibromatosis Syndrome (HFS) is a rare autosomal recessive disorder affecting primarily skin and mucous membranes. Skin appears thickened with subcutaneous nodules, associated with swollen joint contractures, red hyperpigmentation and gingival hyperplasia. Additional findings include osteopenia and osteoporosis, and the affected children are susceptible to infections and protein losing enteropathy (1). Histopathology of skin lesions shows proliferation of spindle-shaped cells, embedded in a homogeneous hyaline-like material, and biochemical alterations in type I and VI collagens as well as in glycosaminoglycans have been reported (2, 3). Initially, infantile systemic hyalinosis and juvenile systemic hyalinosis were considered as two distinct entities on the basis of time of onset. However, subsequent work demonstrated that both forms of hyalinosis were caused by mutations in the CMG2 gene (also known as ANTXR2), indicating that these disorders are allelic and part of the same phenotypic spectrum, now known as HFS (4, 5).