FN1 gene encodes for the formation of fibronectin which is a protein of the extracellular matrix. It is essential to the formation of cartilaginous tissues and bones. Mutations in FN1 affect the stability of fibronectin, the assembly on the cell and can result in accumulation of fibronectin in the cell. Accumulation of fibronectin in cartilage cells or renal cells is thought to be deleterious. The regions in the FN1 gene in which the mutation occurs explains the difference in clinical characteristics between SMDCF and GFND2. Variants in the type-I domain cause SMDCF.
SMDCF is inherited in an autosomal dominant manner which means that only one copy of the gene must carry the mutations for the disease to occur.
FN1-SMDCF