Polygene

A polygene, multiple factor, multiple gene inheritance, or quantitative gene is a group of non-epistatic genes that together influence a phenotypic trait. The precise loci or identities of the non-allelic genes are often unknown to biologists. Advances in statistical methodology and high throughout sequencing are, however, allowing researchers to locate candidate genes for the trait. These genes are generally pleiotropic as well. The genes that contribute to type 2 diabetes are thought to be mostly polygenes.

Traits with polygenic determinism correspond to the classical quantitative characters, as opposed to the qualitative characters with monogenic or oligogenic determinism. In essence instead of two options, such as freckles or no freckles, there are many variations. Like the color of skin, hair, or even eyes.

Inheritance

Polygenic inheritance occurs when one characteristic is controlled by two or more genes. Often the genes are large in quantity but small in effect. Examples of human polygenic inheritance are height, skin color, eye color and weight. Polygenes exist in other organisms, as well. Drosophila, for instance, display polygeny with traits such as wing morphology, bristle count and many others.