Contribution of retrotransposition to developmental disorders

Area of Science:

• Genetics
• Molecular Biology
• Developmental Biology

Background:

• Mobile genetic elements (MEs) are DNA segments capable of retrotransposition (RT).
• While RT is linked to some human disorders, its role in severe developmental disorders (DD) remains largely unexplored.
• Understanding ME activity is crucial for diagnosing genetic conditions.

Purpose of the Study:

• To investigate the impact of RT-derived events in individuals with severe developmental disorders.
• To identify novel ME insertions and gene retroduplications associated with DD.
• To estimate the genome-wide germline ME mutation rate and selective constraints.

Main Methods:

• Exome sequencing of 9738 trios with DD-affected probands.
• Identification and analysis of de novo mobile genetic element insertions and gene retroduplications.
• Estimation of mutation rates and selective pressures on coding ME events.

Main Results:

• Nine de novo MEs were identified, with four likely causative of DD symptoms (0.04% of cases).
• Two de novo gene retroduplications were also discovered.
• Coding ME events exhibit purifying selection signatures comparable to truncating mutations.

Conclusions:

• Retrotransposition plays a role in severe developmental disorders, with potential diagnostic implications.
• This study provides a framework for analyzing the evolutionary impact of MEs on protein-coding genes.
• Further research into ME activity can enhance our understanding of genetic disease and evolution.