With this interactive map we present and summarize all the LP frequency data reported in the scientific literature until July 2020. This tool incorporates detailed information on the geographical location, ethnicity, number of individuals analyzed, reported frequency and reference for each included study. Interactive mapping involves zooming in and out, panning around, identifying specific features, and querying underlying data. Therefore, our tool allows the generation of detailed reports and other means of using or visualizing information in a map. This allows a more attractive way of presenting large sets of data that would not be enough-well exploited in static plots or large tables.
For optimal use, we recommend zooming the map until reaching the desired geographical location or country, and then investigate all reported frequencies. If there is more than one study available in a particular location, data will be displayed in the form of an interactive grey cluster. The number of studies included in each cluster is indicated with a number within the circle. The geographical location mapped for all the studies of a cluster can be visualized as a blue area when moving the mouse over the circle.
The genetic basis for population variation in lactase production as a dominant trait is well-described although not yet complete, with cis-element mutations responsible for LP identified in the transcriptional enhancer MCM6
Among identified variants, the -13910:C>T (rs4988235) and -13495:C>T (rs4954490) have almost reached fixation in some parts of Europe, while others such as -13907:C>G (rs41525747), -13915:T>G (rs41380347), -14009:T>G (rs869051967) and -14010:G>C (rs145946881) are found at variable frequencies in the Middle East and Africa. Besides highlighting as the most widespread and strongly associated LP variants, these six SNPs have been reported as functional markers according to a great range both in vitro transfection assays and in vivo studies.
For them, we created an interactive map following the same format than the one previously-presented for LP phenotype data.
Again, for optimal use, we recommend zooming the map until reaching the desired geographical location or country, and then investigate all reported frequencies. If there is more than one study available in a particular location, data will be displayed in the form of an interactive grey cluster. The number of studies included in each cluster is indicated with a number within the circle. The geographical location mapped for all the studies of a cluster can be visualized as a blue area when moving the mouse over the circle.
References:
Anguita-Ruiz A, Aguilera CM, Gil Á. Genetics of Lactose Intolerance: An Updated Review and Online Interactive World Maps of Phenotype and Genotype Frequencies. Nutrients. 2020;12(9):E2689. Published 2020 Sep 3. doi:10.3390/nu12092689
