Using human sequencing to guide craniofacial research.

Area of Science:

• Genetics
• Developmental Biology
• Bioengineering

Background:

• Technological advancements, including next-generation sequencing and CRISPR-Cas9 genome editing, have transformed the study of human craniofacial development.
• Congenital craniofacial anomalies are increasingly amenable to genetic investigation due to reduced sequencing costs and enhanced genome editing capabilities.

Purpose of the Study:

• To summarize current genetic research approaches for craniofacial development.
• To investigate a novel craniofacial syndrome with a dominant inheritance pattern using genetic and animal modeling techniques.

Main Methods:

• Whole exome and genome sequencing were used to identify genetic variants in patients with craniofacial anomalies.
• CRISPR-Cas9 technology was employed to generate mouse models with specific genetic alterations, including a novel deletion allele of Amotl1.
• Phenotypic analysis of genetically modified mice was performed to assess gene function and pathogenicity.

Main Results:

• Genomic analysis identified a potential causal variant in AMOTL1 in a family with a novel craniofacial syndrome.
• Amotl1 is not essential for mouse survival to weaning.
• Mice carrying the human variant of AMOTL1 exhibited reduced survival rates before weaning, though the cause of death remains unclear.

Conclusions:

• The study highlights the power of integrating human genetic data with animal models for craniofacial research.
• Uncertainty regarding the cause of death in mouse models complicates the direct interpretation of pathogenicity for the human index patient.
• Current craniofacial genetic research faces both significant opportunities and confounding factors that require careful consideration.