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apolipoprotein E genotype

Indications: 1) confirmation of hyperlipoproteinemia type 3 2) assessment of genetic component of atherosclerosis 3) evaluation of late-onset familial Alzheimer's disease Contraindications: - APOE genotyping to predict Alzheimer disease [7] Clinical significance: - the E2/E2 gentotype in conjunction with elevated serum cholesterol, VLDL cholesterol & triglycerides confirms diagnosis of type 3 hyperlipoproteinemia - patients with E2/E2 & E4/E4 genotype are prone to atherosclerosis - risk of late onset familial Alzheimer's disease (AD) is associated with the apo E4 allele - each apo-E4 allele confers a 3-4-fold increased risk of AD [8] - most patients with AD do not carry the apo E4 allele [8] - 48% overall, 61% in Northern Europe [9] Complications: - genotyping does not appear to increase patient distress significantly [2] - knowlege of genotype does affect symptom complaints & test performance [6]: - both performance & assessment of performance are worse with knowing they carry the apo E4 genotype [6]

Related

apolipoprotein E (APOE) apolipoprotein-E gene

General

genotyping (allele testing)

References

  1. Apo E Geotyping Lab Tests Online: apoe
  2. Green RC et al Disclosure of APOE genotype for risk of Alzheimer's disease. N Engl J Med 2009 Jul 16; 361:245. PMID: 19605829 - Kane RA and Kane RL. Effect of genetic testing for risk of Alzheimer's disease. N Engl J Med 2009 Jul 16; 361:298. PMID: 19605835
  3. Cassidy MR et al Comparing test-specific distress of susceptibility versus deterministic genetic testing for Alzheimer's disease. Alzheimers Dement. 2008 Nov;4(6):406-13. PMID: 19012865
  4. Caselli RJ, Dueck AC, Osborne D, et al. Longitudinal modeling of age-related memory decline and the APOE epsilon4 effect. N Engl J Med Jul 16 2009; 361(3):255-263. PMID: 19605830
  5. ARUP Consult: Apolipoprotein E Genotyping, Cardiovascular Disease Risk https://arupconsult.com/ati/apolipoprotein-e-genotyping-cardiovascular-disease-risk
  6. Lineweaver TT et al. Effect of knowledge of APOE genotype on subjective and objective memory performance in healthy older adults. Am J Psychiatry 2013 Oct 30 PMID: 24170170
  7. ACGM News. July 10, 2015 ACMG Provides Recommendations on Genetic Testing Through the Choosing WiselyCampaign. https://www.acmg.net/docs/ACMG_ChoosingWisely_Final.pdf
  8. Geriatric Review Syllabus, 9th edition (GRS9) Medinal-Walpole A, Pacala JT, Porter JF (eds) American Geriatrics Society, 2016 - Geriatric Review Syllabus, 11th edition (GRS11) Harper GM, Lyons WL, Potter JF (eds) American Geriatrics Society, 2022
  9. Ward A, Crean S, Mercaldi CJ et al Prevalence of apolipoprotein E4 genotype and homozygotes (APOE e4/4) among patients diagnosed with Alzheimer's disease: a systematic review and meta-analysis. Neuroepidemiology. 2012;38(1):1-17. Review. PMID: 22179327 Free Article