Sex-linked diseases are inherited through one of the "sex chromosomes" -- the X or Y chromosomes. Autosomally inherited diseases are inherited through the non-sex chromosomes (autosomes), pairs 1 through 22.
Dominant inheritance occurs when an abnormal gene from one parent is able to cause disease even though the matching gene from the other parent is normal. The abnormal gene dominates.
Recessive inheritance occurs when both matching genes must be abnormal to produce disease. If only one gene in the pair is abnormal, the disease does not show up or is mild. Someone who has one abnormal gene (but no symptoms) is called a carrier. A carrier can pass this abnormal gene to his or her children.
The term "sex-linked recessive" usually refers to X-linked recessive.
Autosomal dominant Autosomal recessive Chromosome Gene
- Genetic counseling and prenatal diagnosis
Heredity and disease Inheritance Sex-linked dominant
Inheritance - sex-linked recessive; Genetics - sex-linked recessive; X-linked recessive
Review Date: 04/26/2010
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.