A de novo duplication of chromosome 9q34.13-qter in a fetus with Tetralogy of Fallot Syndrome

Abstract

BackgroundPartial duplications of the distal 9q have been rarely reported in literatures. The key features included characteristic facial appearance, long fingers and toes, slight psychomotor retardation, heart murmur et al. But rare severe congenital heart defects (CHD) such as TOF were reported to be associated with 9qter duplications.Case presentationA 23-year-old woman was referred for genetic counseling and prenatal diagnosis at 253/7 weeks of gestation due to her male fetus, diagnosed as Tetralogy of Fallot Syndrome (TOF) by prenatal ultrasound. SNP (Single nucleotide polymorphism) array revealed that the male fetus had a de novo 5.47 Mb duplication at 9q34.13-qter. Meanwhile, non-invasive prenatal testing (NIPT) using low coverage whole genome massively parallel sequencing of circulating cell-free fetal DNA (cffDNA) showed consistent results. Multiplex ligation-dependent probe amplification (MLPA) also confirmed the duplication at 9qter.ConclusionIn this paper, we present an Asian fetus with TOF caused by a de novo 5.47 Mb duplication at 9q34.13-qter. Duplication of 9q34.13-qter should be considered as an etiological diagnosis in the case of TOF. Our prenatal diagnostic findings provide important information for genetic counseling on the male fetus and future pregnancies in this family. Chromosomal microarray analysis (CMA) remains the first-tier clinical diagnostic test for prenatal fetus with suspicious syndromes. We also highlight the high potential application of NIPT in the screening of sub-chromosomal rearrangement.

Clinical and molecular characterization of 12 prenatal cases of Cri‐du‐chat syndrome

“…All genomic coordinates were taken from the human reference sequence. Genes and Online Mendelian Inheritance in Man (OMIM) references were from RefSeq and OMIM entries, respectively (Liu et al., 2016).…”

Integrated CNV-seq, karyotyping and SNP-array analyses for effective prenatal diagnosis of chromosomal mosaicism

“…Genes and Online Mendelian Inheritance in Man (OMIM) references were from Ref-Seq and OMIM entries, respectively. The theoretical values for the detection of a single copy gain or loss were applied as previously reported [13,14].…”

Integrated CNV-seq, Karyotyping and SNP-array Analyses for Effective Prenatal Diagnosis of Chromosomal Mosaicism

“…SNP array was performed using Affymetrix CytoScan®750 K Array (Affymetrix Inc, CA, USA), according to the manufacturers protocol. The theoretical values for the detection of a single copy gain or loss are described as previously reported [9,10].…”