A Member of the University of Maryland Medical System | In Partnership with the University of Maryland School of Medicine

Get answers to your child's growth, nutrition, and feeding behavior questions.
Growth and Nutrition Experts’s Bio | Q&A Archive
Inheritance - autosomal dominant; Genetics - autosomal dominant
Autosomal dominant is one of several ways that a trait or disorder can be passed down through families.
If a disease is autosomal dominant, it means you only need to get the abnormal gene from one parent in order for you to inherit the disease. One of the parents may often have the disease.
Inheriting a disease, condition, or trait depends on the type of chromosome affected (autosomal or sex chromosome). It also depends on whether the trait is dominant or recessive.
A single, abnormal gene on one of the first 22 nonsex chromosomes from either parent can cause an autosomal disorder.
Dominant inheritance means an abnormal gene from one parent is capable of causing disease, even though the matching gene from the other parent is normal. The abnormal gene "dominates" the pair of genes. If just one parent has a dominant gene defect, each child has a 50% chance of inheriting the disorder.
For example, if four children are born to a couple and one parent has an abnormal gene for a dominant disease, statistically two children will inherit the abnormal gene and two children will not. Children who do not inherit the abnormal gene will not develop or pass on the disease.
If someone has an abnormal gene that is inherited in an autosomal dominant manner, then the parents should also be tested for the abnormal gene.
Examples of autosomal dominant disorders include Huntington's disease and neurofibromatosis-1.
See also:
Korf BR. Principles of Genetics. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 37.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).
© 2011 University of Maryland Medical Center (UMMC). All rights reserved.
UMMC is a member of the University of Maryland Medical System,
22 S. Greene Street, Baltimore, MD 21201. TDD: 1-800-735-2258 or 1.866.408.6885