Recessive: A condition that appears only in individuals who have received two copies of a mutant gene, one copy from each parent. The individuals with a double dose of the mutated gene are called homozygotes. Their parents, each with a single dose of the mutated gene, appear normal and are called heterozygotes, or gene carriers.
There are two types of recessive diseases -- autosomal recessive and X-linked recessive -- that describe different patterns of inheritance.
The opposite of recessive is dominant. See also Autosomal recessive; Dominant; and X-linked recessive.