It should be noted, however, that the amino acid substitution predicted by the polymorphism shown to be associated with reduced alcohol-related cancer risk, ADH7 G92A, is a conservative substitution that, based on homology modelling, maps to a region of the protein distal to either the substrate or co-factor binding sites (P.J.B., unpublished observation). As such, the functional relevance of this specific substitution is unclear. It is, of course, possible that this single nucleotide polymorphism is in linkage disequilibrium with a functional polymorphism elsewhere in the ADH7 gene that remains to be identified.
