A novel LTBP2 gene variant in a Turkish family with juvenile-onset open-angle glaucoma.

Background: Juvenile-onset open-angle glaucoma (JOAG) is a rare form of primary open-angle glaucoma (POAG) with an early age of onset before 40 years. Latent transforming growth factor-beta binding protein 2 (LTBP-2) is an extracellular matrix protein with a multi-domain structure and homology to fibrillins. LTBP2 gene variants have been associated with JOAG in a small number of patients. Herein, we report a novel missense variant in the LTBP2 gene in a Turkish family with JOAG.

Materials and methods: Blood samples were obtained from three siblings (a 20-year-old woman with JOAG, 26-year-old man with JOAG, and 15-year-old girl with posterior embryotoxon) for genetic analysis. Their father had moderate-severe POAG and the 24-year-old brother had JOAG. The mother and 32-year-old sister were healthy. Although the parents reported no consanguinity, they come from the same village.

Results: Clinical exome sequencing analysis of the two siblings with JOAG revealed a novel c.607C>T p.(R203C) (rs777450651) homozygous LTBP2 variant, while the variant was heterozygous in their 15-year-old sister. There were no mutations in the MYOC, CYP1B1, or FBN1 genes.

Conclusion: We documented a novel missense mutation in the LTBP2 gene leading to a severe form of JOAG with refractory IOP and progressive optic nerve damage, which seems to show autosomal recessive inheritance.