APOE polymorphism in a rural older population-based sample in India

Area of Science:

• Genetics
• Population Genetics
• Human Genetics

Background:

• Allele frequencies are typically reported from small, non-representative samples, limiting generalizability.
• Understanding genetic variations like apolipoprotein E (APOE) genotype is crucial for population health studies.
• There is a need for reliable genetic data from diverse populations, including India.

Purpose of the Study:

• To determine the distribution of apolipoprotein E (APOE) genotype and allele frequencies in a large, representative, rural, population-based sample in Haryana, India.
• To provide a demographic breakdown of APOE allele frequencies by age, sex, and religious/caste groups.
• To establish a normative genetic background for future gene-disease association studies in the Indian population.

Main Methods:

• Genotyping of the apolipoprotein E (APOE) polymorphism in a sample of 4450 individuals aged 55-95 years.
• Utilizing a well-defined, representative, rural, population-based cohort from Ballabgarh, Haryana, India.
• Analysis of allele frequencies (E*2, E*3, E*4) and their distribution across demographic subgroups.

Main Results:

• The overall allele frequencies for APOE E*2, E*3, and E*4 were 0.039, 0.887, and 0.073, respectively.
• The APOE*4 allele frequency (0.073) is among the lowest reported globally.
• APOE allele frequencies showed no significant variation by age or sex within this study population.

Conclusions:

• This study presents the largest Indian sample genotyped for APOE polymorphism to date.
• The findings provide a valuable, representative genetic dataset for the North Indian population.
• The low APOE*4 frequency has implications for understanding population-specific genetic risk factors and disease associations.