Zonule-Associated Gene Variants in Isolated Ectopia Lentis and Glaucoma

Area of Science:

• Ophthalmology
• Genetics
• Molecular Biology

Background:

• Ectopia lentis (EL) is a condition affecting the eye's lens, often associated with genetic factors.
• Secondary glaucoma can arise from EL, posing significant risks to vision.
• Understanding the genetic underpinnings of EL is crucial for diagnosis and management.

Purpose of the Study:

• To investigate the genetic mechanisms behind isolated ectopia lentis (EL) and secondary angle closure glaucoma in three Han Chinese families.
• To identify novel gene variants associated with these ocular conditions.

Main Methods:

• Recruitment of three Han Chinese families presenting with EL and glaucoma.
• Comprehensive ocular and physical examinations of all participants.
• DNA extraction and screening for causative variants using whole exome and Sanger sequencing.
• In silico analysis to predict the impact of identified variants on protein structure and function.

Main Results:

• Identification of three novel variants in fibrillin-1 (FBN1) and latent transforming growth factor-β-binding protein 2 (LTBP2) genes.
• Specific mutations found: FBN1 (c.6493G>T:p.(V2165L)) in family 1, FBN1 (c.2543C>A:p.(T848N)) in family 2, and compound heterozygous mutations in LTBP2 (c.4825T>A:p.(C1609S) / c.529T>C:p.(W177R)) in family 3.
• All identified variants are predicted to affect protein structure and function, contributing to EL and secondary glaucoma.

Conclusions:

• The study identified novel FBN1 and LTBP2 gene mutations linked to isolated EL and secondary angle closure glaucoma.
• These findings expand the known spectrum of variants in zonule-related genes.
• The results contribute to a better understanding of the molecular pathology underlying EL and associated glaucoma.