Intestinal lactase deficiency.
D002239:Carbohydrate Metabolism, Inborn Errors; D006026:Glycoside Hydrolases; D006801:Humans; D007422:Intestines / Q000201:enzymology*; D007785:Lactose; D007787:Lactose Intolerance; D008297:Male; D008875:Middle Aged
D006026:Glycoside Hydrolases; D007785:Lactose