collagenopathy

Collagenopathy is a term used for inherited disorders caused by defects in the genes that encode collagen chains or in the enzymes and processes that modify, assemble, or regulate collagen. Collagens are the main structural proteins of connective tissues, providing tensile strength to skin, bone, tendons, cartilage, vessels, and many organs. Because different collagen types are distributed in different tissues, the clinical features of collagenopathies vary widely in severity and pattern.

The most well-known examples include osteogenesis imperfecta, typically caused by mutations in COL1A1 or COL1A2, which leads to bone fragility and fractures and may be accompanied by blue sclerae, dentinogenesis imperfecta, and short stature. Ehlers-Danlos syndromes arise from mutations in several collagen or collagen-processing genes (such as COL5A1, COL5A2 for the classical type, and COL3A1 for the vascular type), with joint hypermobility, skin hyperextensibility, and tissue fragility as common features. Other collagenopathies involve COL2A1 and COL11A1/2 (Stickler and related chondrodysplasias) and COL4A3-5 (Alport syndrome affecting kidneys, ears, and eyes). Less common conditions may involve defects in collagen-modifying enzymes or assembly factors.

Diagnosis combines clinical evaluation, family history, and genetic testing (targeted gene panels, whole-exome or genome sequencing). Sometimes skin or tissue analysis is used to assess collagen structure or production. Management is supportive and multidisciplinary, focusing on fracture prevention, physical therapy, orthopedic and dental care, cardiovascular or renal surveillance where indicated, and genetic counseling. The prognosis depends on the specific subtype and organ involvement.