Phenotypic Variability and Paternal Inheritance of a CHD8 Variant Causing Intellectual Developmental Disorder With Autism and Macrocephaly Confirmed by Epigenetic and Structural Analyses. Mol Genet Genomic Med 2025 Dec;13(12):e70165
Date
12/18/2025Pubmed ID
41407309Pubmed Central ID
PMC12711360DOI
10.1002/mgg3.70165Scopus ID
2-s2.0-105025171807 (requires institutional sign-in at Scopus site)Abstract
BACKGROUND: Intellectual developmental disorder with autism and macrocephaly (IDDAM, OMIM #615032) is an autosomal dominant neurodevelopmental disorder characterized primarily by intellectual disability, autism spectrum disorder, macrocephaly, tall stature, gastrointestinal symptoms, and variable neurological manifestations. Most cases result from de novo pathogenic variants in CHD8.
METHODS: We conducted genome sequencing through the Undiagnosed Diseases Network (UDN) in a female proband harboring a CHD8 variant of uncertain significance (VUS), whose clinical presentation was consistent with IDDAM but included atypical features such as ptosis and hearing loss. Variant pathogenicity was further evaluated using EpiSign DNA methylation analysis and structural biology modeling.
RESULTS: Genome sequencing confirmed the CHD8 variant inherited from her father, who exhibited a subtle feature, including traits consistent with attention-deficit/hyperactivity disorder. Pathogenicity was confirmed through epigenetic signature testing (EpiSign), demonstrating characteristic methylation patterns and structural biology analysis, predicting significant protein destabilization.
CONCLUSION: We describe the case of IDDAM caused by a paternally inherited CHD8 variant. Our findings highlight the importance of considering parental inheritance in IDDAM diagnoses and suggest epigenetic and structural biology analyses as valuable tools for reclassifying VUS when variant pathogenicity remains uncertain.
Author List
Furuta Y, Ezell KM, Hamid R, Cogan JD, Cassini TA, Rives L, McMinn A, Shah S, Peltier AC, Layfield S, Fletcher RS, Tedder ML, Louie RJ, Lee JA, Kerkhof J, Rzasa J, Sadikovic B, Al Mamun A, Sheehan JH, Moth CW, Meiler J, Vawter-Lee M, Mendoza-Sengco PM, Holzen JB, Pruthi S, Phillips JA 3rd, Tinker RJ, Undiagnosed Diseases NetworkAuthor
Michael T. Zimmermann PhD Director, Associate Professor in the Data Science Institute department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Autistic DisorderDNA Methylation
DNA-Binding Proteins
Epigenesis, Genetic
Female
Humans
Intellectual Disability
Male
Megalencephaly
Paternal Inheritance
Pedigree
Phenotype
Transcription Factors
