Mutations in SPATA13/ASEF2 cause primary angle closure glaucoma.

Area of Science:

• Genetics and Ophthalmology
• Molecular Biology
• Cell Biology

Background:

• Primary angle-closure glaucoma (PACG) accounts for approximately 50% of global glaucoma-induced blindness.
• The genetic basis for PACG has remained largely unknown, hindering effective diagnosis and treatment strategies.

Purpose of the Study:

• To identify the causative gene responsible for primary angle-closure glaucoma (PACG).
• To investigate the molecular mechanisms by which mutations in the identified gene contribute to PACG pathogenesis.

Main Methods:

• Employed genetic linkage analysis and whole-genome sequencing to pinpoint the causal gene in a large family.
• Performed mutation screening in an independent cohort of PACG patients.
• Utilized cell line and tissue expression analysis, and studied protein localization during mitosis.

Main Results:

• Identified Spermatogenesis Associated Protein 13 (SPATA13), also known as ASEF2, as the causal gene for PACG.
• A specific 9 bp deletion in SPATA13 was found in all affected individuals, alongside eight additional mutations in unrelated PACG cases.
• SPATA13 mutations were shown to increase RAC1-dependent guanine nucleotide exchange factor (GEF) activity, impacting cellular homeostasis.

Conclusions:

• SPATA13 plays a critical role in regulating mitosis and maintaining tissue homeostasis.
• Mutations in SPATA13 dysregulate GEF activity, leading to the development of primary angle-closure glaucoma.
• This discovery provides a crucial genetic link for PACG and opens avenues for future therapeutic interventions.