combined osteogenesis imperfecta and Ehlers-Danlos syndrome 2

Combined osteogenesis imperfecta and Ehlers-Danlos syndrome 2 is a connective tissue disorder that primarily affects the bones, skin, and other supporting structures. It is linked to pathogenic variants in the COL1A2 gene, which plays a key role in the production of type I collagen. The condition typically presents in childhood and does not show a sex predilection. Precise prevalence estimates are not well established, and the manifestation of symptoms can vary widely among affected individuals.

Individuals with this condition consistently exhibit features such as hyperextensible skin, bruising susceptibility, dermal translucency, blue sclerae, and joint hypermobility. Many affected individuals also experience recurrent fractures, while some may have poor wound healing, joint dislocations, generalized hypotonia, and short stature. Arterial rupture, though less common, remains a significant concern. Not all individuals experience all features, and severity varies considerably.

This condition is caused by pathogenic variants in the COL1A2 gene, which encodes a fundamental component of type I collagen critical for the normal structure and function of bones, skin, and connective tissues. It is inherited in an autosomal dominant pattern, meaning that a single copy of the altered gene is sufficient to result in the disorder. While each affected individual has a 50% chance of passing the variant to their offspring, the severity and range of symptoms can vary considerably between individuals. Genetic counseling is recommended to help families understand the implications and recurrence risks associated with this inheritance pattern. Associated genes include COL1A2.