milk

GLAD

Global Lactase persistance Association Database

Lactase persistence (LP) is the ability of adult humans to digest the milk sugar lactose. LP is a dominant Mendelian trait that has been a subject of extensive genetic, medical, and evolutionary research.

This is an online database resource that will be updated every 3 months and will present the full LP phenotypic and LP-associated allele frequency data known to date, including worldwide interpolated LP frequencies and genotype-phenotype correlation maps. 

We encourage researchers to send us new LP phenotype data to yitan@rockefeller.edu in an Excel format using headers identical to those in the tables linked below. If the contributions are more recent than Itan et al. (2010) please quote its corresponding reference.

Please make sure that the submitted phenotype data conform to the following criteria:

-Random sampling.
-Known ethnicity and sampling location.
-Indigenous population.
-No hospital patients or individuals self reporting with gut problems.


The maps and data presented below were first published in A worldwide correlation of lactase persistence phenotype and genotypes. BMC Evol Biol 10: 36, and are carefully selected following the criteria as stated in Lactose digestion and the evolutionary genetics of lactase persistence. Human Genetics. Vol 124:579–591.

LP Maps
LP Phenotypes
LP Genotypes
LP Ancient Genotypes

 Last update: 12th July 2013: LP Ancient Genotypes. Grateful thanks to Favia Domizia Nardi for providing a correction.