A Mutation in VWA1, Encoding von Willebrand Factor A Domain-Containing Protein 1, Is Associated With Hemifacial...

Area of Science:

• Genetics and Developmental Biology
• Craniofacial Development
• Rare Diseases

Background:

• Hemifacial microsomia (HFM) is a rare congenital disorder affecting first and second pharyngeal arch development, occurring in 1 in 5,600 live births.
• Significant knowledge gaps exist regarding the genetic basis of HFM.

Purpose of the Study:

• To identify novel pathogenic genes associated with Hemifacial Microsomia (HFM).
• To investigate the functional role of the VWA1 gene in craniofacial development.

Main Methods:

• Whole exome sequencing (WES) was employed on a five-generation pedigree.
• VWA1 gene function was assessed using zebrafish models (morpholino and CRISPR/Cas9) and in silico protein structure prediction.
• Craniofacial development pathways were analyzed, including cranial neural crest cell (CNCC) proliferation and pharyngeal chondrocyte organization.

Main Results:

• A novel point mutation (c.G905A:p.R302Q) in the VWA1 gene was identified as a candidate cause of HFM.
• VWA1 mutation predicted to alter WARP protein structure and function, with potential interactions in the FGF pathway.
• Zebrafish VWA1 knockdown/knockout resulted in pharyngeal cartilage deformities, reduced CNCC proliferation, and altered pharyngeal chondrocytes.

Conclusions:

• The study implicates VWA1 mutations in the etiology of Hemifacial Microsomia.
• VWA1's role in suppressing CNCC proliferation and organizing pharyngeal chondrocytes is crucial for normal craniofacial development.