DOMINANT

A trait that is expressed in a person when only one copy of a gene is present; as opposed to a recessive trait which is expressed only when two copies of a particular gene are present. Examples of dominantly-inherited disorders include achondroplasia (a common form of dwarfism), familial hypercholesterolemia (high blood cholesterol in families leading to premature coronary artery disease) and Huntington disease (a form of progressive dementia).