학술논문

Structural Chromosomal Rearrangements Require Nucleotide-Level Resolution: Lessons from Next-Generation Sequencing in Prenatal Diagnosis
Document Type
article
Source
American Journal of Human Genetics. 99(5)
Subject
Biological Sciences
Biomedical and Clinical Sciences
Genetics
Genetic Testing
Pediatric
Human Genome
Clinical Research
Prevention
Biotechnology
Alleles
Chromosome Aberrations
Chromosome Mapping
Congenital Abnormalities
Female
Gene Expression Regulation
Gene Rearrangement
Genome
Human
Genomics
High-Throughput Nucleotide Sequencing
Humans
Karyotyping
Male
Nucleotides
Pregnancy
Prenatal Diagnosis
SOX9 Transcription Factor
Sequence Analysis
DNA
Translocation
Genetic
Medical and Health Sciences
Genetics & Heredity
Biological sciences
Biomedical and clinical sciences
Health sciences
Language
Abstract
In this exciting era of "next-gen cytogenetics," integrating genomic sequencing into the prenatal diagnostic setting is possible within an actionable time frame and can provide precise delineation of balanced chromosomal rearrangements at the nucleotide level. Given the increased risk of congenital abnormalities in newborns with de novo balanced chromosomal rearrangements, comprehensive interpretation of breakpoints could substantially improve prediction of phenotypic outcomes and support perinatal medical care. Herein, we present and evaluate sequencing results of balanced chromosomal rearrangements in ten prenatal subjects with respect to the location of regulatory chromatin domains (topologically associated domains [TADs]). The genomic material from all subjects was interpreted to be "normal" by microarray analyses, and their rearrangements would not have been detected by cell-free DNA (cfDNA) screening. The findings of our systematic approach correlate with phenotypes of both pregnancies with untoward outcomes (5/10) and with healthy newborns (3/10). Two pregnancies, one with a chromosomal aberration predicted to be of unknown clinical significance and another one predicted to be likely benign, were terminated prior to phenotype-genotype correlation (2/10). We demonstrate that the clinical interpretation of structural rearrangements should not be limited to interruption, deletion, or duplication of specific genes and should also incorporate regulatory domains of the human genome with critical ramifications for the control of gene expression. As detailed in this study, our molecular approach to both detecting and interpreting the breakpoints of structural rearrangements yields unparalleled information in comparison to other commonly used first-tier diagnostic methods, such as non-invasive cfDNA screening and microarray analysis, to provide improved genetic counseling for phenotypic outcome in the prenatal setting.