Journal Article

Partial trisomy 4q and monosomy 5p inherited from a maternal translocationt(4;5)(q33; p15) in three adverse pregnancies

Zhang, Jingbo, Zhang, Bei, Liu, Tong, Zhai, Jingfang, Xie, Huihui

2020

Overview

Background Carriers of balanced reciprocal chromosomal translocations are at known reproductive risk for offspring with unbalanced genotypes and resultantly abnormal phenotypes. Once fertilization of a balanced translocation gamete with a normal gamete, the partial monosomy or partial trisomy embryo will undergo abortion, fetal arrest or fetal malformations. We reported a woman with chromosomal balanced translocation who had two adverse pregnancies. Prenatal diagnosis was made for her third pregnancy to provide genetic counseling and guide her fertility. Case presentation We presented a woman with chromosomal balanced translocation who had three adverse pregnancies. Routine G banding and CNV-seq were used to analyze the chromosome karyotypes and copy number variants of amniotic fluid cells and peripheral blood. The karyotype of the woman was 46,XX,t(4;5)(q33;p15). During her first pregnancy, odinopoeia was performed due to fetal edema and abdominal fluid. The umbilical cord tissue of the fetus was examined by CNV-seq. The results showed a genomic gain of 24.18 Mb at 4q32.3-q35.2 and a genomic deletion of 10.84 Mb at 5p15.2-p15.33 and 2.36 Mb at 15q11.1-q11.2. During her second pregnancy, she did not receive a prenatal diagnosis because a routine prenatal ultrasound examination found no abnormalities. In 2016, she gave birth to a boy. The karyotype the of the boy was 46,XY,der(5)t(4;5)(q33;p15)mat. The results of CNV-seq showed a deletion of short arm of chromosome 5 capturing regions 5p15.2-p15.33, a copy gain of the distal region of chromosome 4 at segment 4q32.3q35.2, a duplication of chromosome 1 at segment 1q41q42.11 and a duplication of chromosome 17 at segment 17p12. During her third pregnancy, she underwent amniocentesis at 17 weeks of gestation. Chromosome karyotype hinted 46,XY,der(5)t(4;5)(q33;p15)mat. Results of CNV-seq showed a deletion of short arm (p) of chromosome 5 at the segment 5p15.2p15.33 and a duplication of the distal region of chromosome 4 at segment 4q32.3q35.2. Conclusions Chromosomal abnormalities in three pregnancies were inherited from the mother. Preimplantation genetic diagnosis is recommended to prevent the birth of children with chromosomal abnormalities.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Amniocentesis / Amniotic fluid / Analysis / Balanced translocation, partial trisomy 4q, monosomy 5p, Cri-du-Chat syndrome / Biomedical and Life Sciences / Biomedicine / Birth / Birth defects / Case Report / Chromosome 1 / Chromosome 17 / Chromosome 4 / Chromosome 5 / Chromosome banding / Chromosome deletion / Chromosome translocations / Chromosomes / Clinical genetics / Copy number / Cytogenetics / Deoxyribonucleic acid / Diagnosis / DNA / Edema / Fertility / Fertilization / Fetuses / Gene duplication / Genetic counseling / Genetic screening / Genomes / Genotype & phenotype / Genotypes / Gestation / Human Genetics / Hydrops fetalis / Infertility / Intellectual disabilities / Karyotypes / Laboratories / Medical genetics / Microcephaly / Miscarriage / Molecular Medicine / Monosomy / Peripheral blood / Phenotypes / Pregnancy / Pregnant women / Prenatal diagnosis / Ultrasonic imaging / Ultrasound / Umbilical cord