dominant

The dominant - A term used in genetics to describe the characteristics of a gene. Many characteristics are determined by a single pair of genes, one of each pair being inherited from each parent. The dominant gene of the pair overrides its equivalent recessive gene, allowing it to be expressed.

For example, the gene for brown eye colour is dominant, so that if a child inherits the gene for brown eyes from one parent and the gene for blue eyes from the other parent, he or she will have brown eyes.

Some genetic disorders are determined by a dominant abnormal gene that overrides the effect of an equivalent normal gene that is recessive. Examples of such disorders include Marfan syndrome and Huntington’s disease. In this case, a child will have the disease if he or she inherits the gene from one or both parents.