Somatic Mosaicism and Autism Spectrum Disorder.

Area of Science:

• Genetics
• Neurodevelopmental Disorders
• Genomic Medicine

Background:

• Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with a significant genetic component.
• Initially, research focused on germline mutations present in all cells, detectable in blood or saliva.
• Emerging evidence highlights the role of de novo somatic mutations, which arise postzygotically and are present in a subset of cells.

Purpose of the Study:

• To explore the contribution of de novo somatic variants to autism spectrum disorder (ASD) risk.
• To investigate the potential of somatic mutations as genetic markers for ASD.
• To understand the role of somatic mutations in ASD pathogenesis and therapeutic targeting.

Main Methods:

• Analysis of de novo germline and somatic variants using next-generation sequencing.
• Investigation of variant detection in clinically accessible tissues (blood, saliva) and postmortem brain tissue.
• Assessment of somatic mutation frequency in simplex ASD cases and their tissue-specific distribution.

Main Results:

• De novo germline variants are established contributors to ASD.
• De novo somatic mutations are implicated in ASD risk, potentially accounting for 3-5% of simplex cases.
• Brain-limited somatic mutations have been identified in postmortem brain tissue, suggesting tissue-specific effects.

Conclusions:

• Somatic mutations represent a significant genetic factor in a proportion of unexplained ASD cases.
• Brain-limited somatic mutations serve as valuable markers for discovering ASD risk genes and pathways.
• Understanding somatic mutations can inform targeted therapeutic strategies for ASD.