Forgot to mention before that there are quite a few of us out there without this valuable little enzyme. What happens then?
Well.. I know there are three expressions of the alcohol dehydrogenase enzyme gene, fast, medium, and slow, as they are called.. People with the 'slow' expression increase their risk of heart disease when they consume alcohol, while people with fast and medium expressions decrease their risk of heart disease with moderate consumption of alcohol. How this relates to methanol toxicity I don't know. Alcohol processing is a system, more than just a single enzyme, so its likely that it would still be toxic, and its likely that ethanol would still depress that systems ability to handle methanol simultaneously. However, thats just a guess. I wouldn't take your enzymatic status to mean you are invulnerable to methanol, however.
peace,
sam