Molecular Genetics of Gucy2d Gene among Patients with Leber Congenital Amaurosis Attending National Eye Center Kaduna

Leber congenital amaurosis (LCA) is a clinically and genetically heterogeneous disease that presents with the autosomal recessive pattern of inheritance. There are about 19 genes responsible for the pathogenic cause of the disease, with mutations in a few of the genes recorded. The study aims to identify the GUCy2d gene in patients with Leber Congenital Amaurosis attending the National Eye Center Kaduna, Nigeria. In this purposive sampling method made up of patients of all ages and sexes diagnosed with Leber congenital amaurosis or retinal dystrophy, DNA was extracted from the whole blood according to the manufacturer’s guide (Bioneer USA). DNA was PCR-multiplexed by using primers designed as microsatellite markers to identify the GUCY2D gene, gel electrophoresed and sequenced to identify mutations. Multiple sequence alignment was carried out on the DNA sequence which was translated to protein sequence using MegaX software. The PCR products' band sizes correlated with the amplicon size of the genetic marker. After sequencing the Gucy2d gene, it was aligned with the reference gene obtained from the gene bank and mutations were identified in some positions. Gucy2d gene harbouring mutations were identified in the diseased patients, which resulted in the change in the translation of some of the Amino acid sequences.