A gene linked to Alzheimer’s Disease may impact cognitive health much sooner than previously realized.
The APOE gene creates a protein, apolipoprotein E, which packages cholesterol and other fats to transport them through the bloodstream. There are three versions, or alleles, of APOE. One of those is the APOE4 allele, present in about 15 percent of the population. APOE4 carriers are up to three times more likely to develop late-onset Alzheimer’s disease, which occurs in people 65 and older.
It’s been demonstrated the gene is linked to changes in cognitive ability that are noticeable as early as one reaches his or her 50s. But new research from UCR professor Chandra Reynolds and her colleagues holds that APOE4 starts manifesting much earlier—before adulthood.
In the journal Neurobiology of Aging, Reynolds asserts that those carrying the APOE4 gene score lower on IQ tests during childhood and adolescence. And the effect was stronger in girls than in boys.
The study involved analysis of three to four decades-old studies, the Colorado Adoption Project and the Longitudinal Twin Study, that included genotyping data from 1,321 participants when they were 6 ½ to 18 years old. Gender among participants was split almost evenly, and 92 percent of the participants were white, with 8 percent from other races. The findings are based on three IQ assessments between childhood and adolescence.
Read more at University of California - Riverside