The genomic landscape of balanced cytogenetic abnormalities associated with human congenital anomalies.

Nat Genet
Authors
Abstract

Despite the clinical significance of balanced chromosomal abnormalities (BCAs), their characterization has largely been restricted to cytogenetic resolution. We explored the landscape of BCAs at nucleotide resolution in 273 subjects with a spectrum of congenital anomalies. Whole-genome sequencing revised 93% of karyotypes and demonstrated complexity that was cryptic to karyotyping in 21% of BCAs, highlighting the limitations of conventional cytogenetic approaches. At least 33.9% of BCAs resulted in gene disruption that likely contributed to the developmental phenotype, 5.2% were associated with pathogenic genomic imbalances, and 7.3% disrupted topologically associated domains (TADs) encompassing known syndromic loci. Remarkably, BCA breakpoints in eight subjects altered a single TAD encompassing MEF2C, a known driver of 5q14.3 microdeletion syndrome, resulting in decreased MEF2C expression. We propose that sequence-level resolution dramatically improves prediction of clinical outcomes for balanced rearrangements and provides insight into new pathogenic mechanisms, such as altered regulation due to changes in chromosome topology.

Year of Publication
2017
Journal
Nat Genet
Volume
49
Issue
1
Pages
36-45
Date Published
2017 Jan
ISSN
1546-1718
DOI
10.1038/ng.3720
PubMed ID
27841880
PubMed Central ID
PMC5307971
Links
Grant list
K99 MH095867 / MH / NIMH NIH HHS / United States
P01 GM061354 / GM / NIGMS NIH HHS / United States
R00 MH095867 / MH / NIMH NIH HHS / United States
R01 HD081256 / HD / NICHD NIH HHS / United States