HUMAN CYTOCHROME P4501B1 (CYP1B1) AND MYOCILIN (MYOC) GENES MUTATIONS POTENTIAL DIAGNOSTIC TOOL FOR GLAUCOMA DISEASE IN NIGERIAN POPULATIONS: A MOLECULAR EPIDEMIOLOGY APPROACH

Background: Glaucoma is one of the world’s leading causes of irreversible blindness. A complex, multifactorial disease, underlying pathogenesis and reasons for disease progression are not fully understood. Glaucoma bring about elevated intraocular pressure; leading to optic nerve damage and functional vision loss. In different populations, CYP1B1 and MYOC genes mutations had been associated with glaucoma presentations. There is paucity of updated information on genetic polymorphisms of CYP1B1 and MYOC genes mutations and their association with glaucoma in different Nigerian populations. Thus, this research seeks to investigate on human cytochrome P4501B1 (CYP1B1) and Myocilin (MYOC) genes mutations among glaucoma cases in Nigerian populations.
Methods: Cases and controls were recruited from Abuja (North Central); where patients from Jalingo (North East Nigeria) and Calabar (South-south). Genomic DNA extraction, PCR amplifications and sequencing of CYP1B1 and MYOC genes were carried out. Chromatograms were decoded into nucleotide sequences using ChromaPro software. Multiple sequence and pairwise alignments were performed using MEGA X software and Codon-Code Aligner software for SNPs analysis. 
Results: Male and female glaucoma case was 19 (59.4%) and 13 (40.6%) respectively. The overall prevalence was 46.9% (15/32) and 43.8% (14/32) for CYP1B1 and MYOC genes mutations respectively. CYP1B1 gene mutation variants detected included g.291G>C (p. His97Glu), g.344C>T (p. Thro115Met), g.317delT and g.378-380delATG. MYOC gene mutation variants detected included g.299T>G (p. Gly102Arg), g.595A>C (p. Gln202His), g.513G>T (p. Gln171Pro) and g.341-347delTATACTG. 
Conclusion: Glaucoma in Nigerian populations across different ethnic groups harbors CYP1B1 and MYOC genes mutations; and some were novel missense mutations. This study will help to establish the contribution of CYP1B1 and MYOC genes mutations in molecular etiology of glaucoma in Nigerian populations. The information can serve as referral for future study.