what chromosome is lactose intolerance on
This gene on chromosome 2 codes for the enzyme lactase. This enzyme enables infants to break down lactose, the main sugar in milk. In people who are lactose tolerant, the gene remains active throughout their lives.In most people who are lactose intolerant, the gene is turned off after infancy, making the digestion of dairy products difficult and painful.his enzyme enables infants to break down lactose, the main sugar in milk. In people who are lactose tolerant, the gene remains active throughout their lives. In most people who are lactose intolerant, the gene is turned off after infancy, making the digestion of dairy products difficult and painful.