LactoGen

Food intolerance to lactose is due to the lack of the enzyme lactase in the microvilli of the small intestine and thus the inability to break down lactose into glucose and galactose. With age there can be a progressive genetically determined reduction in lactase activity, leading to an acquired intolerance.
The correlation between single nucleotide base polymorphisms (SNPs) at the promoter level of the gene for the enzyme Lactase (MCM6) and the LPN (Lactase Non-Persistence) phenotype has been known since 2002.