Trisomy 10: first-trimester features on ultrasound, fetoscopy and postmortem of a case associated with increased nuchal translucency.

We report a case of the prenatal diagnosis of trisomy 10 in a fetus presenting with an increased nuchal translucency thickness (5 mm) on a routine first-trimester anomaly scan at 12 weeks' gestation. Multiple abnormalities were diagnosed by ultrasound and fetoscopy. Karyotyping on chorionic villus sampling led to the diagnosis of homogeneous trisomy 10 which was confirmed by in situ hybridization on fetal tissue samples. Postmortem examination confirmed major anatomical malformations, including facial cleft, arthrogryposis of the upper and lower limbs and bilateral diaphragmatic hernia, and also revealed hypoplastic lungs, right renal agenesis and a complex cardiac malformation. Trisomy 10 is an uncommon chromosomal abnormality that is likely to be associated with increased fetal nuchal translucency. This case also emphasizes the value of a detailed anomaly scan in high-risk patients in the first trimester of pregnancy.