Who is this MTHFR gene mutation and why is it more common than you think? Up to 60% of the population carries a mutation in the MTHFR gene, which plays a MTHFR Gene Polymorphisms: A Single Gene with Wide Ranging Clinical ImplicationsA Review The MTHFR Gene Growing Healthy Together Long Beach The detox gene (MTHFR) is rendered inactive when your diet is high in meat. Our diet should be 80% plant based or higher. MTHFR Gene Mutation and Enzyme Activity At Home Health Tests