Abstract

Sequence-based genetic testing identifies causative variants in ~ 50% of individuals with developmental and epileptic encephalopathies (DEEs). Aberrant changes in DNA methylation are implicated in various neurodevelopmental disorders but remain unstudied in DEEs. We interrogate the diagnostic utility of genome-wide DNA methylation array analysis on peripheral blood samples from 582 individuals with genetically unsolved DEEs. We identify rare differentially methylated regions (DMRs) and explanatory episignatures to uncover causative and candidate genetic etiologies in 12 individuals. Using long-read sequencing, we identify DNA variants underlying rare DMRs, including one balanced translocation, three CG-rich repeat expansions, and four copy number variants. We also identify pathogenic variants associated with episignatures. Finally, we refine the CHD2 episignature using an 850 K methylation array and bisulfite sequencing to investigate potential insights into CHD2 pathophysiology. Our study demonstrates the diagnostic yield of genome-wide DNA methylation analysis to identify causal and candidate variants as 2% (12/582) for unsolved DEE cases.

Original languageEnglish
Article number6524
JournalNature Communications
Volume15
Issue number1
DOIs
StatePublished - Dec 2024

Funding

FundersFunder number
Estate of Ernest Hyam Davis
Tedd and Mollie Carr Endowment Trust
Seqirus and Nutricia
Cure Kids New Zealand
University of Washington Center for Rare Disease Research
National Institutes of Health
Health Research Council of New Zealand
Australian Epilepsy Research Foundation
St. Jude Hartwell Center
Health Research Council of New Zealand and Cure Kids New Zealand
Office of Strategic Coordination
St. Jude Graduate School of Biomedical Sciences
Citizens United for Research in Epilepsy
GRIN2B foundation
National Human Genome Research InstituteU24 HG011746, UM1 HG006493, U01 HG011744
Memphis Research ConsortiumMR/Y008170/1
Manchester Biomedical Research CentreNIHR203308
OfficeDP5OD033357, GNT1172897, U01HG007942, U01HG007709
National Health and Medical Research CouncilGNT2010562, GNT2006841
American Epilepsy Society919453

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