Send to a Friend Print this Page

X-linked Dominant: Incontinentia Pigmenti

Genes are inherited from our biological parents in specific ways. One of the basic patterns of inheritance of our genes is called X-linked dominant inheritance.

What is X-linked dominant inheritance?

X-linked dominant inheritance occurs when a gene responsible for a trait or disorder is located on the X chromosome. The gene acts in a dominant manner. This means that both males and females can display the trait or disorder when they have only one copy of the gene inherited from a parent.

Genetic illustration demonstrating X-linked dominant inheritance
Click Image to Enlarge

Depending on the disorder, a gene that is X-linked dominant may cause a pregnancy with a male not to survive. Scientists and doctors say that there is "lethality" in males. This means that the gene can be passed from mother to daughter, but if passed to a son, then the pregnancy miscarries. Only those sons without the gene survive and are born healthy. One example of an X-linked dominant condition is called incontinentia pigmenti (IP).

What is incontinentia pigmenti?

IP is extremely rare. The main features occur in the skin where a blistering rash occurs in newborns. This is followed by the blisters becoming raised, like warts. Next, brown swirls appear in the skin, followed by the appearance of light-colored swirls. The result is a "marble-cake–like" appearance on the skin. Other health problems can be seen in IP involving the eyes, central nervous system, teeth, nails, and hair. The severity varies from person to person.

Online Source: U.S. National Library of Medicine Genetics Home Referencehttp://ghr.nlm.nih.gov/handbook/inheritance/inheritancepatterns <a href="" target="_blank"></a>
Online Source: National Center for Biotechnology Informationhttp://www.ncbi.nlm.nih.gov/books/NBK1472/ <a href="" target="_blank"></a>
Online Editor: Kochman, Marilyn
Online Medical Reviewer: Clark, Heather, MS, CGC
Online Medical Reviewer: newMentor board-certified, academically affiliated clinician
Date Last Reviewed: 6/29/2013
© 2000-2014 The StayWell Company, LLC. 780 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.