Use of Genetic Variation as Biomarkers for Mild Cognitive Impairment and Progression of Mild Cognitive Impairment to Dementia

Issue title: Similarities and Differences Between Mild Cognitive Impairment and Alzheimer's Disease

Guest editors: Mark A. Lovell

Article type: Research Article

Authors: Reitz, Christiane^{a; b; c} | Mayeux, Richard^{a; b; c; d; e; *}

Affiliations: [a] Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA | [b] Department of Neurology, College of Physicians and Surgeons, Columbia University, NY, USA | [c] Gertrude H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, NY, New York, USA | [d] Department of Epidemiology, Joseph P. Mailman School of Public Health, Columbia University, NY, New York | [e] Department of Psychiatry, College of Physicians and Surgeons, Columbia University, NY, New York, USA | Sanders-Brown Center on Aging and Alzheimer's Disease Center, Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA

Correspondence: [*] Correspondence to: Richard Mayeux, MD, MSc, Gertrude H. Sergievsky Center, 630 West 168th Street, Columbia University, New York, NY 10032, USA. Tel.: +1 212 305 3192; Fax: +1 212 305 2518; E-mail: rpm2@columbia.edu.

Abstract: Cognitive impairment is prevalent in the elderly. The high estimates of conversion to dementia have spurred the interest in identification of genetic risk factors associated with development of cognitive impairment and or its progression. However, despite notable achievements in human genetics over the years, in particular technological advances in gene mapping and in statistical methods that relate genetic variants to disease, to date only a small proportion of the genetic contribution to late-life cognitive impairment can be explained. A likely explanation for the difficulty in gene identification is that it is a multifactorial disorder with both genetic and environmental components, in which several genes with small effects each are likely to contribute to the quantitative traits associated with the disease. The motivation for identifying the underlying genetic risk factors elderly is clear. Not only could it shed light on disease pathogenesis, but it may also provide potential targets for effective treatment, screening, and prevention. In this article we review the current knowledge on underlying genetic variants and the usefulness of genetic variation as diagnostic tools and biomarkers. In addition, we discuss the potentials and difficulties researchers face in designing appropriate studies for gene discovery.

Keywords: Alzheimer's disease, APOE, cognition, genes, mild cognitive impairment, SORL1

DOI: 10.3233/JAD-2010-1255

Journal: Journal of Alzheimer's Disease, vol. 19, no. 1, pp. 229-251, 2010