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

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 age-related diseases. The association of XRCC1 gene with age-related 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.