Autosomal dominant intellectual disability.

Area of Science:

• Genetics
• Neuroscience
• Developmental Biology

Background:

• Intellectual disability (ID) is a complex neurodevelopmental disorder characterized by significant impairments in cognitive and adaptive functioning.
• Its prevalence ranges from 1.5-2% for milder forms (IQ < 70) to 0.3-0.5% for severe forms (IQ < 50).
• Recent advances in next-generation sequencing, including whole exome sequencing (WES) and whole genome sequencing (WGS), have accelerated the discovery of genes associated with various forms of ID.

Purpose of the Study:

• To highlight the impact of advanced sequencing technologies on identifying intellectual disability genes.
• To discuss the diagnostic utility of trio exome sequencing for sporadic ID cases.
• To emphasize the need for further research in gene discovery, pathway elucidation, and therapeutic development for ID.

Main Methods:

• Review of recent advancements in genetic technologies for ID gene identification.
• Analysis of mutation detection rates for de novo mutations using trio exome sequencing.
• Discussion of current challenges and future directions in ID research.

Main Results:

• Over 650 autosomal dominant ID (ADID) genes have been identified, with an estimated 350 yet to be discovered.
• Trio WES demonstrates a mutation detection rate of 20-60% for de novo mutations in individuals with sporadic ID.
• The classification of ADID genes based on clinical findings is feasible, but gene selection for analysis remains challenging.

Conclusions:

• Next-generation sequencing technologies have significantly advanced the identification of genes underlying intellectual disability.
• Trio exome sequencing is a valuable tool for diagnosing sporadic ID, particularly for detecting de novo mutations.
• Continued research is crucial for uncovering the remaining ID genes, understanding disease mechanisms, and developing effective therapies for rare causes of ID.