In normal pregnancy, end-diastolic flow appears in the umbilical artery around the 13th week of gestation, with a velocity which increases progressively with advancing gestation. The detection of reversed flow in the umbilical artery, the highest expression of an increase in placental vascular resistance, is extremely uncommon in the first half of gestation and, in three of the four cases reported in the literature, there were chromosomal abnormalities. We report a new case of reversed end-diastolic flow in the umbilical artery in a 13-week fetus with increased nuchal translucency thickness, megacystis and tachycardia. Cytogenetic analysis of chorionic villi and amniocytes revealed trisomy 13. The findings provide further evidence for a possible association between reversed end-diastolic flow in the umbilical artery and chromosomal abnormalities. However, the effectiveness of this potential marker in an unselected population requires further evaluation.

We report the use of comparative genomic hybridization (CGH) to define the extra chromosome region present in two de novo partial trisomies 15q25-qter and Xp21-pter, which could not be clarified by conventional G-banding. Investigation with fluorescence in situ hybridization (FISH) revealed that the partial trisomy corresponded to an unbalanced translocation between Y and 15 chromosomes in 1 patient and an unbalanced X/X reorganization in the other patient. The combination of classical karyotyping, CGH, and FISH is useful for the identification and characterization of partial trisomies in clinical diagnostic laboratories, in order to delineate the chromosome regions implicated in specific clinical disorders.

1q44 deletion is a rare syndrome associated with facial dysmorphism and developmental delay, in particular related with expressive speech, seizures, and hypotonia (ORPHA:238769). Until today, the distinct genetic causes for the different symptoms remain not entirely clear. We present a patient with a 2.3-Mb 1q44 deletion, including AKT3, ZBTB18, and HNRNPU, who shows microcephaly, developmental delay, abnormal corpus callosum, and seizures. The genetic findings in this case and a review of the literature spotlight a region between 243 Mb and 245 Mb on chromosome 1q related to the genesis of the typical symptoms of 1q44 deletion.

These results demonstrate the safety and usefulness of laser methodology in preimplantation genetic diagnosis.

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