The heritability of abstract reasoning in Caribbean Latinos with familial Alzheimer disease.
BACKGROUND
Alzheimer disease (AD) is under substantial genetic influence. To better understand the genetic influence on component phenotypes of AD, we estimated the heritability (h(2)) of abstract reasoning and examined its relation with apolipoprotein epsilon 4 (APOE-epsilon 4).


METHODS
We studied abstract reasoning in 1,116 individuals from 210 Caribbean Hispanic families with late onset AD, using the similarities subtest scores from the Wechsler Adult Intelligence Scale. We computed h(2), then performed analysis of variance to examine the effect of APOE-epsilon 4.


RESULTS
Abstract reasoning was highly heritable (h(2)(unadjusted) = 79.9%). After adjusting for covariates, the h(2) was reduced to 32.6%, with education accounting for 40.8% of the variance. The APOE-epsilon 4 allele had no effect.


CONCLUSIONS
Abstract reasoning was strongly influenced by genetic factors and education. Genes other than APOE contribute to the inheritance of abstract reasoning ability.
Johnson
Beverly
B
Taub Institute on Alzheimer's Disease and the Aging Brain, New York, NY, USA.
Santana
Vincent
V
Schupf
Nicole
N
Tang
Ming-X
MX
Stern
Yaakov
Y
Mayeux
Richard
R
Lee
Joseph H
JH
D000368:Aged; D000544:Alzheimer Disease / Q000208:ethnology* / Q000235:genetics*; D017691:Caribbean Region / Q000208:ethnology; D003072:Cognition Disorders / Q000175:diagnosis / Q000208:ethnology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004522:Educational Status; D005260:Female; D006630:Hispanic or Latino / Q000208:ethnology* / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011340:Problem Solving; D012720:Severity of Illness Index; D017678:Sex Distribution; D014481:United States / Q000453:epidemiology