Screening of the LTBP2 gene in a north Indian population with primary congenital glaucoma

PURPOSE: Primary congenital glaucoma (PCG), a severe form of glaucoma that presents early in life, is an autosomal recessive eye disorder that results from defects in anterior eye segment. Null mutations in LTBP2 were reported in patients with PCG in Pakistani and Iranian families. This study was aimed to identify the mutation profile of the LTBP2 gene in north Indian patients with PCG. METHODS: After ethical clearance, 54 unrelated patients with PCG who were either negative or heterozygous for MYOC, CYP1B1, and FOXC1 mutations and 50 ethnically matched non-glaucomatous controls were recruited for the study. PCG diagnosis was established by the presence of buphthalmos in at least one affected eye and associated high intraocular pressure before the age of 3 years. LTBP2 was screened in genomic blood DNA for mutations, with PCR and direct sequencing of PCR amplified fragments. RESULTS: We observed one intronic single nucleotide polymorphism (rs3742793) between exons 6 and 7 in the LTBP2 gene in 18 patients with PCG. This nucleotide change resulted in cytosine (C) being replaced by guanosine (G) at position g.75070493. No pathogenic variants were identified in the LTBP2 gene in our cohort of patients. CONCLUSIONS: LTBP2 gene mutations are not involved in the pathogenesis of primary congenital glaucoma in our patients. Thus, it is important to screen other glaucoma-associated loci and genes for involvement in congenital glaucoma in cases that are either negative or heterozygous for MYOC, CYP1B1, and FOXC1 mutations to have better insight into the disease pathogenesis.