Severity of Cognitive Deficits, Disability, and Apolipoprotein E Gene Polymorphisms in Dementia: A Hospital Based Cross-Sectional Study of Predominant Rural Patients

Background: Late-onset Alzheimer’s disease causes progressive cognitive decline and functional impairment, with the Apolipoprotein E (APOE) ε4 allele as its major genetic risk factor. The study is designed with primary objective to assess the prevalence and correlation between APOE ε4 and ε2 polymorphisms and secondary objective is to evaluate the degree of cognitive impairment and disability in dementia patients in predominant rural cohort. Methodology: This cross-sectional study enrolled 30 patients diagnosed with dementia at a tertiary care hospital in Karnataka. Cognitive deficits were evaluated cross-sectionally using the Hindi Mental State Examination (HMSE) and severity was determined by Dementia Severity Rating Scale (DSRS). Disability assessment was done using World Health Organization-Disability Assessment scale 2.0. Genetic analysis of APOE polymorphisms (rs429358 and rs7412) was performed via polymerase chain reaction and Sanger sequencing. Results: Eight three percentage of participants found to have moderate-to-severe dementia. Increased cognitive deficits were associated with higher disability scores across multiple domains shown by significant correlation both HMSE and DSRS scores ( P < 0.001). On genetic analysis of twenty seven patients, 37% had prevalence of ε4 allele and 11% had ofε2 allele. Ten individuals had mutations in rs429358 and three individuals had mutations in rs7412. Conclusion: Functional disabilities in dementia patients due to cognitive deficits causes’ significant burden and adjusted years lived with disability. Presence of Apo ε4 polymorphism and single nucleotide polymorphisms mutations in more than one-third of participants indicates a strong genetic vulnerability and predictor of illness progression. These findings presses need for genetic and cognitive screening for individual at risk of dementia in restricted resource rural areas.