A case of chondrodysplasia punctata with features of osteogenesis imperfecta type II

The osteogenesis imperfecta syndromes constitute a group of heterogeneous, heritable skeletal dysplasias. Of the 4 types, type II is the most severe, with an incidence of 1 per 55,000. It is characterized by malformed bones secondary to abnormal collagen type I synthesis. Affected fetuses are divided into 3 groups: A, B, and C. All groups have long bones described as "wrinkled" or "crumpled" secondary to repeated fractures. Many bones also show evidence of demineralization, which is especially evident in the bones of the face and calvaria. In groups A and C, the chest is generally small, with thickened and shortened ribs, and each rib has characteristic "beading" patterns secondary to repeated fracturing. Sonography has traditionally been successful in the diagnosis of osteogenesis imperfecta at an early gestational age. Chondrodysplasia punctata describes a heterogeneous group of skeletal disorders characterized by abnormal mineralization of bones during gestation. There are many different causes of it, but some of the specific subtypes include rhizomelic, X-linked dominant (also known as Conradi-Hünermann syndrome), X-linked recessive, and tibia-metacarpal. We report a case of severe X-linked dominant chondrodysplasia punctata, which sonographically had common features with osteogenesis imperfecta type II.