Increased nuchal translucency thickness: a potential indicator for Ritscher-Schinzel syndrome.

Objective: The Ritscher-Schinzel syndrome (RSS), also known as the 3C syndrome, is an autosomal recessive disorder classically comprising craniofacial, cerebellar and cardiac defects. The underlying molecular etiology remains unknown; therefore, prenatal diagnosis of recurrences depends on identification of the associated structural anomalies on second trimester ultrasound examination. Identification of recurrences using first-trimester ultrasound has not been reported previously.

Methods: Two women who presented at our center with fetal nuchal abnormalities on first trimester ultrasound went on to have children with RSS. One of the women had also undergone a previous pregnancy termination for fetal anomalies consistent with RSS. The ultrasound findings and details of these 3 cases were reviewed.

Results: Both cases of RSS and the third suspected case were found to have nuchal abnormalities on first-trimester scan. All went on to develop malformations consistent with RSS detectable on second-trimester ultrasound. The later 2 cases continued to term and the children had facial characteristics consistent with RSS.

Conclusion: First-trimester ultrasound assessment of nuchal translucency could be considered as a method for identifying sib recurrences of RSS. In addition, RSS should be on the differential diagnosis when increased nuchal translucency is seen on first-trimester scan.