These genes participate in a wide variety of biological processes including the detoxification of exogenously and endogenously generated aldehydes.

[8] There is a mutant form of aldehyde dehydrogenase, termed ALDH2*2, wherein a lysine residue replaces a glutamate in the active site at position 487 of ALDH2.

The patients show higher blood levels of acetaldehyde, and become violently ill upon consumption of even small amounts of alcohol.

Yokoyama et al. found that decreased enzyme activity of aldehyde dehydrogenase-2, caused by the mutated ALDH2 allele, contributes to a higher chance of esophageal and oropharyngolaryngeal cancers.

[11] Demir et al. found that ALDH1 is a potentially important, poor prognostic factor in breast cancer, associated with high histological grade, estrogen/progesteron receptor negativity and HER2 positivity.

[13] Moreover, ALDH gene, protein expression and activity are substantially decreased in the substantia nigra of Parkinson's disease patients.

[14] These reports are in line with findings implementing toxic lipid oxidation-derived aldehydes in these diseases and in neurodegeneration in general.

Mice null for ALDH1a1 and ALDH2 exhibit Parkinson's disease-like age-dependent deficits in motor performance and significant increase in biogenic aldehydes.

[17] The ALDH2-/- mice display age-related memory deficits in various tasks, as well as endothelial dysfunction, brain atrophy, and other Alzheimer's disease-associated pathologies, including marked increases in lipid peroxidation products, amyloid-beta, p-tau and activated caspases.

These behavioral and biochemical Alzheimer's disease-like deficits were efficiently ameliorated when the ALDH2-/- mice were treated with isotope-reinforced, deuterated polyunsaturated fatty acids (D-PUFA).