Ultrasound diagnosis of severe mesomelic dysplasia in two fetuses, associated with increased neck translucency and tetralogy of Fallot in one and cystic hygroma in the other.

Two stillborn male sibling fetuses born to the same parents had severe mesomelic dysplasia documented at ultrasound and confirmed by radiography and autopsy. The 17-week-old fetus with increased neck translucency had additional heart and great vessel anomalies consistent with tetralogy of Fallot. The 15-week-old fetus had a nuchal cystic hygroma. We posit that these sibs have a distinct, previously unreported skeletal dysplasia. The mode of genetic transmission could be autosomal recessive or X-linked recessive.