Page "Lactase" Paragraph 11

Some population segments exhibit lactase persistence resulting from a mutation that is postulated to have occurred 5000-10, 000 years ago, coinciding with the rise of cattle domestication.

This mutation has allowed almost half of the world ’ s population to metabolize lactose without symptoms.

Studies have linked the occurrence of lactase persistence to two different single-nucleotide polymorphisms about 14 and 22 kilobases upstream of the 5 ’- end of the LPH gene.

Both mutations, C → T at position-13910 and T → A at position-22018, have been independently linked to lactase persistence.