Study sheds light on distribution of Alzheimer’s gene in Latino populations

A gene associated with Alzheimer’s disease appears to vary significantly from one Latino population to the next, according to a new study that sheds light on the distribution of the gene in this understudied population.  The gene, called the apolipoprotein E (apoE) gene, is also associated with an increased risk for heart disease and high cholesterol.

Although Latinos as a group are more likely than whites to develop Alzheimer’s and Alzheimer’s related dementia, Latino genetic diversity has been understudied, the researchers note. In the current study, the researchers tested for the apoE gene in nearly 11,000 individuals with diverse and well-defined Latino ancestry from four metropolitan areas in the United States—the Bronx, Chicago, Miami, and San Diego. The participants, who were middle-aged and older, were part of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), a comprehensive study of Hispanic/Latino health and disease in the United States.

The researchers found that Dominican, Puerto Rican, and Cuban individuals tended to have higher frequencies of the apoE gene. The apoE gene codes for several different proteins, including apoE4, a well-known risk factor for Alzheimer’s and cognitive decline. The risky apoE4 gene was present at almost 18 percent frequency in Dominicans, while Cubans (12.6 percent) and Puerto Ricans (13.3 percent) carried the gene at intermediate frequency.  The gene appeared much less common in individuals from Mexico, Central America, and South American, with apoE4 gene frequencies of around 11 percent.

The findings shed light on this understudied ethnic group and provides the basis for future studies of the apoE gene in this fast-growing segment of the U.S. populations, the researchers say.  Their study, supported in part by NHLBI, appeared in Scientific Reports, a publication of Nature.