Genetics & Alzheimer’s disease

The exact cause of Azheimer’s disease is still unknown; however, research shows a higher prevalence among those with a family history of it, so here we explore how genetics affect Alzheimer’s disease.

What causes Alzheimer’s disease?

Alzheimer’s disease (AD) is the most common cause of dementia, which is characterized by impaired memory, inability to perform routine daily tasks and behavioral changes. Though the exact cause is still unknown, the incidence of AD has been noted to increase with aging.

Epidemiology

The prevalence of dementia is estimated at 25 million people globally and AD accounts for two out of three cases. It may be categorized as familial (inherited) or sporadic (new onset) and the vast majority of cases of have no known cause.

Some authors have also reported early onset AD in patients with Down’s syndrome that is attributable to alterations in amyloid precursor protein (APP) genes in chromosome 21. APP genetic mutation has also been noted in individuals with hereditary AD.

What changes occur in the brain in AD?

Previous studies have demonstrated an increased amount of plaques known as neurofibrillary tangles in the brains of people with AD.

Do genetics affect Alzheimer’s disease?

The genetic mechanisms of AD have not been well elucidated. However, genetic studies have identified an autosomal dominant inheritance pattern in AD and APP and presenilin (PSEN) genes among individuals with increased amounts of amyloid plaques in the brain, and thus the association with the pathogenesis of AD.

What is the cure for AD?

Currently there is no known cure, or treatment options that delay the onset or slow the progression of AD.

References

1. https://www.clinicalguidelines.gov.au/
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3. Tanzi RE, Gusella JF, Watkins PC, Bruns GA, St George-Hyslop P, Van Keuren ML, Patterson D, Pagan S, Kurnit DM, Neve RL. Amyloid beta protein gene: cDNA, mRNA distribution, and genetic linkage near the Alzheimer locus. Science. 1987: 235: 880-884.
4. Holtzman DM, Goate A, Kelly J, Sperling R. Mapping the road forward in Alzheimer’s disease. Science translational medicine. 2011: 3
5. Bertram L, Lill CM, Tanzi RE. The genetics of Alzheimer disease: back to the future. Neuron. 2010: 68: 270-281.
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8. Holtzman DM, Morris JC, Goate AM. Alzheimer’s disease: the challenge of the second century. Science translational medicine. 2011: 3
9. Levy-Lahad E, Wasco W, Poorkaj P, Romano DM, Oshima J, Pettingell WH, Yu CE, Jondro PD, Schmidt SD, Wang K, et al. Candidate gene for the chromosome 1 familial Alzheimer’s disease locus. Science. 1995: 269: 973-977.
10. Sherrington R, Rogaev EI, Liang Y, Rogaeva EA, Levesque G, Ikeda M, Chi H, Lin C, Li G, Holman K, Tsuda T, Mar L, Foncin JF, Bruni AC, Montesi MP, Sorbi S, Rainero I, Pinessi L, Nee L, Chumakov I, Pollen D, Brookes A, Sanseau P, Polinsky RJ, Wasco W, Da Silva HA, Haines JL, Perkicak-Vance MA, Tanzi RE, Roses AD, Fraser PE, Rommens JM, St George-Hyslop PH. Cloning of a gene bearing missense mutations in early-onset familial Alzheimer’s disease. Nature. 1995: 375: 754-760.
11. Tanzi RE, Gusella JF, Watkins PC, Bruns GA, St George-Hyslop P, Van Keuren ML, Patterson D, Pagan S, Kurnit DM, Neve RL. Amyloid beta protein gene: cDNA, mRNA distribution, and genetic linkage near the Alzheimer locus. Science. 1987: 235: 880-884

 

Last Reviewed: 05-May-2017