Prenatal diagnosis of a supernumerary aberrant chromosome 9

For counselling of parents, as well as to basically understand how chromosome aneuploidies affect embryonic or fetal development, it is of great importance to analyse and collect genotypes of fetuses with clinical anomalies. This report describes the first prenatal diagnosis of a supernumerary chromosome 9 with deletion of the chromosome region 9q34. Ultrasound examination in the 13th week of gestation detected increased nuchal translucency of 6.9 mm, fetal ascites and a pronounced facial anomaly. Hysteroscopic examination before curettage made it possible to describe this facial anomaly as a double-sided, median defect of the superior lip with protrusion of parts of intersegments. This report provides evidence that the absence of trisomy 9 in 9q34 does not prevent abnormal facial development.