Identification of an episignature for the MEF2C-associated syndrome

Neurodevelopmental disorder with hypotonia, stereotypic hand movements, and impaired language (NEDHSIL), also known as MEF2C-related disorder or MEF2C haploinsufficiency syndrome (MCHS), is a condition caused by pathogenic variants in the Myocyte Enhancer Factor-2C (MEF2C) gene. This study aimed to identify a DNA methylation episignature specific to NEDHSIL and explore its similarities with other known episignatures. Genome-wide DNA levels were assessed in a cohort of patients with MEF2C mutations and controls, and differentially methylated CpG sites were identified. A bioinformatic analysis yielded a classifier that was trained against controls and other known episignature disorders within the EpiSign Knowledge Database. The classifier demonstrated high accuracy, sensitivity, and specificity in classifying NEDHSIL samples. Furthermore, functional annotation and comparative analysis revealed similarities between the NEDHSIL episignature and other genetic neurodevelopmental disorders. This study provides evidence for a DNA methylation episignature specific to NEDHSIL and highlights the potential utility of this epigenetic biomarker for diagnosing and understanding molecular pathophysiology of neurodevelopmental disorders associated with MEF2C mutations.