De novo mutations in PLXND1 and REV3L cause Möbius syndrome

Area of Science:

• Genetics
• Neuroscience
• Developmental Biology

Background:

• Möbius syndrome (MBS) is a rare neurological disorder characterized by facial nerve paralysis and congenital anomalies.
• The underlying cause of MBS has been debated, with genetic and non-genetic etiologies considered.
• Previous research has not definitively identified the genetic basis for most MBS cases.

Purpose of the Study:

• To investigate the genetic etiology of Möbius syndrome.
• To identify specific genes and pathways involved in MBS pathogenesis.
• To explore the developmental mechanisms underlying MBS.

Main Methods:

• Whole-exome sequencing and genetic analysis of MBS patients.
• Identification of de novo mutations in candidate genes.
• Analysis of Plxnd1 and Rev3l mutant mouse models to study hindbrain development.

Main Results:

• Identified de novo mutations in PLXND1 and REV3L genes in a subset of MBS patients.
• PLXND1 is involved in neural migration, while REV3L is crucial for DNA translesion synthesis.
• Mutant mouse models revealed convergence of these pathways at the facial branchiomotor nucleus, affecting motoneuron development.

Conclusions:

• De novo mutations in PLXND1 and REV3L are significant contributors to Möbius syndrome etiology.
• These findings highlight the critical roles of neural migration and DNA repair in hindbrain development.
• Further genetic studies are warranted to identify other causative genes for MBS.