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The COMT Val158 Met polymorphism as an associated risk factor for Alzheimer disease and mild cognitive impairment in

Manuel Fernández Martínez1, Xabier Elcoroaristizabal Martín, Luís Galdos Alcelay

  • 1Neurology Department, Hospital de Cruces, Baracaldo, Vizcaya, Spain. mfernandezm@meditex.es

BMC Neuroscience
|October 2, 2009
PubMed
Abstract

Insights

The catechol-O-methyltransferase (COMT) Val158Met polymorphism is not an independent risk factor for Alzheimer's disease (AD) or mild cognitive impairment (MCI). However, it synergistically interacts with the apolipoprotein E (APOE) epsilon4 allele, increasing AD risk, particularly in women.

Area of Science:

  • Neuroscience
  • Genetics
  • Pharmacology

Background:

  • Alzheimer's disease (AD) and mild cognitive impairment (MCI) are complex neurological disorders.
  • Genetic factors, including the catechol-O-methyltransferase (COMT) and apolipoprotein E (APOE) genes, are implicated in AD and MCI pathogenesis.
  • The COMT Val158Met polymorphism and APOE epsilon4 allele are common genetic variations studied for their potential roles in neurodegenerative diseases.

Purpose of the Study:

  • To investigate the catechol-O-methyltransferase (COMT) Val158Met polymorphism as a risk factor for Alzheimer's disease (AD) and amnestic mild cognitive impairment (MCI).
  • To examine the potential synergistic effect between the COMT Val158Met polymorphism and the apolipoprotein E (APOE) epsilon4 allele in the risk of AD and MCI.
  • To determine if these genetic interactions differ between sexes.

Main Methods:

  • Genotyping of COMT Val158Met and APOE was performed using real-time polymerase chain reaction (rtPCR) and polymerase chain reaction (PCR) with restriction fragment length polymorphism (RFLPs).
  • Participants included 223 MCI patients, 345 AD patients, and 253 healthy controls.
  • Multinomial logistic regression models were employed to analyze the association between genotypes and disease risk.

Main Results:

  • The COMT Val158Met polymorphism alone was not found to be an independent risk factor for AD or MCI.
  • Individuals with high-activity COMT genotypes (GG and AG) showed a synergistic effect with the APOE epsilon4 allele, significantly increasing AD risk (OR = 5.96-6.71).
  • This synergistic effect was more pronounced in women with AD and in men with MCI when combined with the APOE epsilon4 allele.

Conclusions:

  • The COMT Val158Met polymorphism does not independently predict AD or MCI risk.
  • A significant synergistic interaction exists between COMT Val158Met genotypes and the APOE epsilon4 allele, elevating the risk for AD and MCI.
  • The impact of this genetic synergy on disease risk is sex-dependent, being greater in women with AD and men with MCI.

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