Nuchal fold thickness at 14-16 weeks' gestation as measured by transvaginal sonography

Expanding the pre- and postnatal phenotype of WASHC5 and CCDC22 -related Ritscher-Schinzel syndromes

Ritscher-Schinzel syndrome (RTSCS) is a rare genetic condition characterized by peculiar craniofacial features and cerebellar and cardiovascular malformations. To date, four genes are implicated in this condition. The first two genes described were the autosomal recessive inherited gene WASHC5 associated with Ritscher-Schinzel syndrome 1 (RTSCS1), and CCDC22, an X-linked recessive gene causing Ritscher-Schinzel syndrome 2 (RTSCS2). In recent years, two other genes have been identified: VPS35L (RTSCS3) and DPYSL5 (RTSCS4). Only few patients with a molecular diagnosis of RTSCS have been reported, leaving the phenotypical spectrum and genotype-phenotype correlations ill-defined. We expand the number of genetically confirmed patients with RTSCS1 and 2; reporting three live born and three terminated pregnancies from two unrelated families. Four siblings carried compound heterozygous variants in WASHC5 while two siblings harboured a hemizygous CCDC22 variant. The most common findings in all patients were craniofacial dysmorphism, particularly macrocephaly, down slanted palpebral fissures and low set-ears. Developmental delay, intellectual disability and ataxic gait were present in all patients. One of the patients with the CCDC22 variant presented pubertas tarda. Elevation of nuchal translucency was observed in the first trimester ultrasound in three foetuses with compound heterozygous variants in WASHC5. None of the patients had epilepsy. The pre- and postnatal findings of this cohort expand the known phenotype of RTSCS1 and 2, with direct impact on postnatal outcome, management, and familial counseling.

Comparison of Fetal Nuchal Fold Thickness Measurements by Two- and Three-Dimensional Ultrasonography (3DXI Multislice View)

Purpose. To compare the measurements of fetal nuchal fold (NF) thickness by two-dimensional (2D) and three-dimensional (3D) ultrasonography using the three-dimensional extended imaging (3DXI). Methods. A cross-sectional study was performed with 60 healthy pregnant women with a gestational age between 16 and 20 weeks and 6 days. The 2D-NF measurements were made as the distance from the outer skull bone to the outer skin surface in the transverse axial image in the suboccipital-bregmatic plane of the head. For the 3D we employed the 3DXI multislice view software, in which 3 × 2 tomographic planes was displayed on the screen and the distance between the tomographic slices was 0.5 mm. Maximum, minimum, mean, and standard deviation were calculated for 2D and 3D ultrasonography, as well the maximum and minimum, mean, and standard deviation for the difference between both methods. The Wilcoxon signed-rank test was used to compare the two different techniques. Results. 2D-NF showed a mean of thickness of 3.52 ± 0.95 mm (1.69–7.14). The mean of 3D-NF was 3.90 ± 1.02 mm (2.13–7.72). The mean difference between the methods was 0.38 mm, with a maximum difference of 3.12 mm. Conclusion. The NF thickness measurements obtained by 3D ultrasonography were significantly larger than those detected with 2D ultrasonography.