International Psychogeriatrics

  • International Psychogeriatrics (2004), 16 : pp 317-326
  • Copyright © International Psychogeriatric Association 2004
  • DOI: 10.1017/S104161020400033X (About DOI)
  • Published online: 24 September 2004

Table of Contents - 2004 - Volume 16, Issue 03  


Apolipoprotein E polymorphism and age of onset for Alzheimer's disease in a bi-ethnic sample

Dylan G. Harwood a1a2, Warren W. Barker a2c1, Raymond L. Ownby a2a3, Peter St. George-Hyslop a4, Michael Mullan a5 and Ranjan Duara a2a3a6
a1 Neuropsychiatric Institute and Hospital, Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles School of Medicine
a2 The Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center and University of Miami School of Medicine
a3 Department of Psychiatry and Behavioral Sciences, University of Miami School of Medicine
a4 Departments of Medicine and Physiology, Center for Research in Neurodegenerative Diseases, University of Toronto
a5 Roskamp Laboratory, Department of Psychiatry, University of South Florida
a6 Department of Medicine, University of Miami School of Medicine

Article author query
harwood dg   [PubMed][Google Scholar] 
barker ww   [PubMed][Google Scholar] 
ownby rl   [PubMed][Google Scholar] 
george-hyslop ps   [PubMed][Google Scholar] 
mullan m   [PubMed][Google Scholar] 
duara r   [PubMed][Google Scholar] 

Abstract

Objective: This study examined the association between the Apolipoprotein-E [varepsilon]4 allele (APOE [varepsilon]4) and age of disease onset in a bi-ethnic sample of community dwelling Alzheimer's disease (AD) patients.

Design: Cross-sectional study of AD patients evaluated at a University-affiliated outpatient memory disorders clinic.

Subjects: A clinic-based cohort of white non-Hispanic (WNH; n=601) and white Hispanic (WH; n=359) patients diagnosed with possible or probable AD according to NINCDS-ADRDA diagnostic criteria.

Measures: Global cognitive functioning of the subjects was evaluated using the Mini-mental State Exam. The age of onset of AD was calculated from the patient's current age minus the reported duration of disease obtained from a knowledgeable family member.

Results: A significant relationship was discovered between APOE [varepsilon]4 and age of onset for WNH, with lower ages of onset among patients carrying the [varepsilon]4/[varepsilon]4 and [varepsilon]3˜/[varepsilon]4 genotypes in relation to patients with the [varepsilon]3/[varepsilon]3 genotype. The results revealed a more modest effect for APOE genotype in the WH cohort, with a lower age of onset witnessed among [varepsilon]4 positive patients ([varepsilon]2/[varepsilon]4, [varepsilon]3/[varepsilon]4 and [varepsilon]4/[varepsilon]4 genotypes) in comparison to [varepsilon]4 negative patients ([varepsilon]2/[varepsilon]2, [varepsilon]2/[varepsilon]3 and [varepsilon]3/[varepsilon]3 genotypes).

Conclusion: The association between the [varepsilon]4 allele and earlier age of onset was more pronounced in WNH compared to WH patients, suggesting the impact of APOE polymorphism on clinical phenotype may be different for distinct ethnic groups in the U.S.

(Received March 14 2003)
(returned to authors for revision June 3 2003)
(revised version received September 22 2003)
(Accepted October 10 2003)


Correspondence:
c1 Correspondence should be addressed to: Warren Barker, M. A., M. S., Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center, 4300 Alton Road, Miami Beach, FL 33140, U.S.A. Phone: +1 305 674-2592. Fax: +1 305 674-2996.

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