Ehlers-Darlos syndrome characterized by hypermobile joints and skin abnormalities is due to:

Ans. A. Abnormality in gene for procollagenEhlers-Danlos syndrome comprises a group of inherited disorders whose principal clinical features are hyperextensibility of the skin, abnormal tissue fragility, and increased joint mobility. The clinical picture is variable, reflecting underlying extensive genetic heterogeneity. At least 10 types have been recognized, most but not all of which reflect a variety of lesions in the synthesis of collagen. Type IV is the most serious because of its tendency for spontaneous rupture of arteries or the bowel, reflecting abnormalities in type III collagen. Patients with type VI due to a deficiency of lysyl hydroxylase, exhibit marked joint hypermobility and a tendency to ocular rupture. A deficiency of procollagen N- proteinase, causing formation of abnormal thin, irregular collagen fibrils, results in type VII C manifested by marked joint hypermobility and soft skin.