Ehlers-Danlos syndrome is associated with a deficiency in which type of collagen?

Ehlers-Danlos syndrome (EDS) is a group of connective tissue disorders characterized by hyper-elastic skin, joint hypermobility, and a tendency to bruise easily. The underlying pathology involves defects in collagen synthesis or structure. The most common types of EDS are primarily associated with abnormalities in type I and type III collagen.

Type I collagen is a key structural protein found in bones, tendons, ligaments, and skin. It provides tensile strength and resilience to these tissues. Type III collagen, on the other hand, is typically found in skin, blood vessels, and hollow organs, playing a crucial role in maintaining tissue integrity and flexibility. Both types are essential for proper connective tissue function.

In EDS, particularly the classical and hypermobile types, the deficiency or dysfunction of type I and type III collagen is what leads to the hallmark signs and symptoms of the syndrome. Therefore, recognizing that the disorder is related to these two collagen types explains the correct answer.

Other types of collagen, like type II, which is primarily found in cartilage, and type IV, found in basement membranes, are not directly implicated in Ehlers-Danlos syndrome, which is why they do not account for the collagen defects seen in this condition.