Heritability of magnetic resonance imaging (MRI) traits in Alzheimer disease cases and their siblings in the MIRAGE study

Kathryn L. Lunetta, Porat M. Erlich, Karen T. Cuenco, L. Adrienne Cupples, Robert C. Green, Lindsay A. Farrer, Charles DeCarli

Research output: Contribution to journalArticle

24 Scopus citations

Abstract

Magnetic resonance imaging (MRI) traits can serve as more specific measures of degenerative or cerebrovascular brain injury than can be ascertained through personal history, risk factors, clinical signs, or symptoms. They are potentially useful intermediate phenotypes for genetic studies of Alzheimer disease (AD). Recent studies have estimated heritability of white matter hyperintensity (WMH) among cognitively normal family members to be between 0.55 and 0.73. Persons discordant for AD are expected to have substantially different MRI phenotype distributions; our goal was to determine whether MRI traits in siblings discordant for AD are heritable. We measured cerebral atrophy, medial temporal atrophy (MTA), WMH, and a rating of cerebrovascular disease (CVR) via MRI in 815 participants from 424 families of the Multi-Institutional Research in Alzheimer's Genetic Epidemiology Study. Residual heritability after adjustment for covariates ranged from 0.17 (P=0.009) for MTA to 0.57 (P=10) for CVR. The number of APOE-ε4 alleles was significantly associated with WMH (P=0.01) and CVR (P=0.005) but not cerebral atrophy (P=0.25) or MTA (P=0.83). Heritability remained significant and high after adjusting for APOE genotype, suggesting that a substantial proportion of the additive genetic variation in these MRI traits is explained by other genes. In the Multi-Institutional Research in Alzheime's Genetic Epidemiology Study of AD-discordant siblings, MRI traits are heritable and are potential endophenotypes for genetic association studies.

Original languageEnglish (US)
Pages (from-to)85-91
Number of pages7
JournalAlzheimer Disease and Associated Disorders
Volume21
Issue number2
DOIs
StatePublished - Apr 2007

    Fingerprint

Keywords

  • Alzheimer disease
  • APOE
  • Heritability
  • Magnetic resonance imaging

ASJC Scopus subject areas

  • Geriatrics and Gerontology
  • Psychiatry and Mental health
  • Neuroscience(all)

Cite this