The novel p.G150R missense mutation in the cartilage matrix protein subdomain of type VII collagen in compound heterozigosity with the c.682 + 1G > A COL7A1 splicing mutation leads to mild dystrophic epidermolysis bullosa

摘要

Dystrophic epidermolysis bullosa (DEB) is a rare genoderma-tosis characterized by fragility, blistering and abnormal scarring of the skin and mucous membranes, showing different degree of cutaneous and extracutaneous involvement. Several variants have been described , due to dominant (DDEB) or recessive (RDEB) mutations in COL7A1 gene encoding for pro-al (VII) collagen chain . Three identical pro-al (VII) chains, consisting of a central collagenous domain, and two flanking amino- and carboxy-terminal noncollagenous domains (NCI and NC2, respectively), assemble into type VII collagen homotrimers (COLLVII), which aggregate to form anchoring fibrils (AF). These structures ensure the dermal-epidermal adhesion . The NCI globular domain, pointing outwards the AF, is composed by several subdomains with homology to adhesive proteins: a segment with a 40 percent homology to cartilage matrix protein (CMP), nine consecutive fibronectin type IH-like repeats, and a von Willebrand factor motif.