Genetics: Dementia risk may be misestimated in US Latinos

Distributions of variants of the apolipoprotein E (apoE) gene among a large sample of US Latinos Americans are described in a study in Scientific Reports this week. The findings may have important implications for disease risk estimations in this understudied population.

Variants of the apoE gene may have different effects on various disease risks, such as cognitive decline, Alzheimer’s disease and related dementias. Given their potentially broad impact on health and disease, it is important to characterize the distribution of apoE variants in populations with varied ancenstral backgrounds, such as Latinos, in which previous research has produced inconsistent results.

Hector Gonzalez and colleagues examined genetic information from 10,887 Latinos living in four US metropolitan areas. The authors found that the frequency of the apoE4 gene variant, a risk factor for cognitive decline and Alzheimer’s disease-related dementias, varied with ancestral background. apoE4 frequency was highest in Dominicans (17.5%), followed by Puerto Ricans and Cubans (13.3% and 12.6%, respectively), and lowest in Central Americans, South Americans and Mexicans (approximately 11%). The frequency of the apoE2 variant - a putative resilience factor - was highest among Dominicans (8.6%) and Cubans (6.5%), with South Americans (3.6%) and Mexicans (2.9%) having the lowest frequencies.

The findings underscore the need for large studies of US Latinos with different ancestral backgrounds to better understand the nature of the association between Alzheimer’s disease and variants of apoE in the fastest-growing segment of this US population.