Prenatal 3D ultrasound diagnostics in cleidocranial dysplasia.

A 34-year-old Caucasian woman with cleidocranial dysplasia (CCD) and a known family history of CCD was referred for an ultrasound examination in the first trimester of her second pregnancy. Molecular genetic analysis of the RUNX2 gene was non-informative. A routine 2D ultrasound examination carried out at a local hospital at gestational age 12 weeks showed no signs of CCD. A 3D ultrasound examination in week 15+4 showed a fetus with typical CCD features including large fontanelles, lack of nasal bones, clavicles without the typical S-form, as well as severe delay in calvarial ossification, especially in the midline. Serial 3D ultrasound examinations during pregnancy confirmed the diagnosis, and over time the manifestations became even more distinct. The diagnosis was clinically confirmed at birth. This case suggests that the typical craniofacial CCD traits, including wide unmineralized areas in the calvarial midline and missing nasal bones, are easily recognizable using 3D ultrasound as early as in week 15.