## Description

A quantitative trait locus (QTL) is a polymorphic locus that contains alleles which differentially affect the expression of a continuously distributed phenotypic trait. Usually a QTL is a marker described by statistical association to quantitative variation in the particular phenotypic trait that is thought to be controlled by the cumulative action of alleles at multiple loci.

For a comprehensive review of QTL mapping techniques in the rat, see Rapp, J.P. (2000) in the References section below.

## Credits

Thanks to the RGD for providing this annotation. RGD is funded by grant HL64541 entitled "Rat Genome Database", awarded to Dr. Howard J Jacob, Medical College of Wisconsin, from the National Heart Lung and Blood Institute (NHLBI) of the National Institutes of Health (NIH).

## References

Rapp, J.P. Genetic Analysis of Inherited Hypertension in the Rat. Physiol. Rev. 2000 Jan;90(1):135-172.