Molecular Characterisation of X-ray Cross-complementing Group 1 (XRCC1) Gene and Risk Factors in Senile Cataract Patients attending a Tertiary Care Hospital, Uttar Pradesh, India

Abstract

Introduction: Cataract arises because of aging of the crystalline lens of the eye which prevents clear vision. X-ray Cross-complementing Group 1 (XRCC1) is a Deoxyribonucleic Acid (DNA) repair protein which is involved in Single-Strand Breaks (SSBs) and Base Excision Repair (BER) pathway which is responsible for the efficient repair of DNA damage is mainly responsible for cataract in patients. Aim: To study the prevalence, risk factors and the molecular characterisation with its special association to XRCC1 gene in senile cataract patients. Materials and Methods: This was a cross-sectional study carried out in the Department of Anatomy and Ophthalmology, Rama Medical College Hospital and Research Centre, Kanpur, Uttar Pradesh, India, from April 2021 to April 2022. A total of 500 clinical patients were included in which 250 patients were confirmed as cataract positive patients. Venous blood of 5 mL was collected in Ethylene diamine tetra-acetic acid tubes. The DNA extraction for the detection of XRCC1gene was done using Qiagen DNA extraction kit as per manufactures guidelines, which was further confirmed by Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Results: A total of 500 clinically suspected patients were included in which 250 cases were confirmed as cataract positive patients. The ratio of females was more (n=130, 52%) compared to males (n=120, 48%) with the mean age for females with 57.6% and for males with 61.13%. Hypertension (n=173, 69.2%) was the most common disease associated with the cataract patients. The ratio of males were more (n=91, 75.8%) compared to females (n=82, 63.07%). The mean age of males was 64.40 years and that of females were 62.45 years. The other co-morbidity included diabetes (48.8%), in which males constituted 67 (55.83%) participants compared to the females with 55 (42.3%) participants. The presence of XRCC1 gene was detected in all cataract positive patients, which was also confirmed by RT-PCR. Conclusion: The polymorphisms of DNA repair genes decreased their ability to repair DNA damage, leaving human body a greatly increased susceptibility to cancer or agerelated diseases. The association of XRCC1 gene with agerelated cataract susceptibility observed in the present study supports the view that XRCC1 gene plays an important role in susceptibility to age-related cataract, so early screening and its molecular profiling will help the clinician in the early diagnosis as well as early treatment.