Early prenatal diagnosis of a recurrent case of short-rib thoracic dysplasia 3 due to compound heterozygosity for variations in the DYNC2H1 gene: an "ultrasound first" approach

Short-rib thoracic dysplasia 3 with or without polydactyly (OMIM # 613091) represents a clinical spectrum encompassing a heterogeneous group of skeletal dysplasias associated with homozygous or compound heterozygous mutations of DYNC2H1. We describe the case of a couple with two consecutive therapeutic abortions due to a diagnosis of short-rib thoracic dysplasia mutations. In the first pregnancy, the diagnosis has been made at 21 weeks. In the second one, an accurate and early ultrasound examination allowed a diagnosis at 12 weeks. DYNC2H1 mutations were confirmed in both cases. In this report, we underline the importance of an ultrasound evaluation at the end of the first trimester of pregnancy in the detection of early signs of skeletal dysplasias. An early prenatal diagnosis of a short-rib skeletal dysplasia, such as for other severe skeletal dysplasias, is critical to offer a couple the chance of a weighted, informed, and less traumatic decision about the continuation of the pregnancy.