Prenatal diagnosis of partial monosomy 2q (2q37.3→qter) and partial trisomy 10q (10q24.31→qter) of paternal origin associated with increased nuchal translucency and abnormal maternal serum screening results.

OBJECTIVE

We present prenatal diagnosis of terminal 2q deletion and distal 10q duplication of paternal origin in a fetus associated with increased nuchal translucency and abnormal maternal serum screening results.

CASE REPORT: A 26-year-old woman who had experienced spontaneous abortion twice underwent amniocentesis at 16 weeks of gestation because of an increased nuchal translucency thickness of 3.5 mm at 12 weeks of gestation and abnormal maternal serum screening results of 2.573 multiples of the median (MoM) of free β-human chorionic gonadotrophin (β-hCG) and 1.536 MoM of pregnancy-associated plasma protein-A (PAPP-A) resulting in a trisomy 21 risk of 1:64. Amniocentesis revealed a derivative chromosome 2. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed arr [hg19] 2q37.3 (238,294,223-242,782,258) × 1, 10q24.31q26.3 (102,018,246-135,426,386) × 3. Cytogenetic analysis of parental bloods revealed a karyotype of 46,XX in the mother and a karyotype of 46,XY,t(2;10)(q37.3;q24.3) in the father. The fetal karyotype was 46,XX,der(2)t(2;10)(q37.3;q24.3)pat. The pregnancy was terminated at 20 weeks of gestation, and a malformed fetus was delivered with facial dysmorphism. Postnatal analysis of the cord blood confirmed the results of prenatal diagnosis. The fetus had a 4.693-Mb deletion of 2q37.3 encompassing the genes of HDAC4, KIF1A, PASK, HDLBP, FARP2 and D2HGDH, and a 33.34-Mb duplication of 10q24.31-q26.3 encompassing the gene of NFκB2.

CONCLUSION

First-trimester ultrasound and maternal serum biochemistry screening may help to identify an unexpected unbalanced familial translocation at prenatal diagnosis.