MECP2 Regulatory Variants Identified in Male Autism Cases Without Rett Features
A targeted MPRA screen of MECP2 regulatory sequence identified two inherited variants that lower expression by 30 percent and track with autism plus ADHD in males. The results integrate human genetics with prior mouse dosage models to explain part of the male bias without invoking full Rett syndrome. Evidence remains preliminary until replicated in independent cohorts with deeper functional validation.
Because the variants were transmitted from unaffected mothers, the findings illustrate classic X-linked male vulnerability rather than de novo mutation. Larger whole-genome sequencing cohorts will be required to determine how many additional MECP2 regulatory alleles exist and whether similar mechanisms operate at other X-linked or autosomal dosage-sensitive genes. Functional assays such as MPRA remain essential for prioritizing non-coding candidates before expensive animal modeling.
Dr. Zoghbi: Independent replication cohorts will confirm at least three additional MECP2 regulatory variants meeting the same 25-35 percent expression threshold within 18 months.
Sources (2)
- [1]Primary Source(https://www.cell.com/ajhg/fulltext/S0002-9297(26)00345-6)
- [2]Supporting Source(https://www.nature.com/articles/s41588-019-0370-1)