Ask Our Experts

Get answers to your specific medical questions from UM Medical Center experts.

Note: This is for informational purposes only. Doctors cannot provide a diagnosis via e-mail.

Paroxysmal nocturnal hemoglobinuria (PNH)

Definition:

Paroxysmal nocturnal hemoglobinuria is a rare disease in which red blood cells break down earlier than normal.

Alternative Names:

PNH

Causes, incidence, and risk factors:

Persons with this disease have blood cells that are missing a gene called PIG-A. This gene allows a substance called glycosyl-phosphatidylinositol (GPI) to help certain proteins stick to cells.

Without PIG-A, important proteins cannot connect to the cell surface and protect the cell from destructive substances in the blood. The result is a break down of blood cells.

The disease can affect people of any age. It may be confused with aplastic anemia , and may turn into myelodysplastic syndrome or acute myelogenous leukemia .

Risk factors, except for prior aplastic anemia, are not known.

References:

US Food and Drug Administration. FDA Approves First-of-its-Kind Drug to Treat Rare Blood Disorder . Rockville, MD: National Press Office; March 16, 2007. Release P07-47.

Hillmen P, Young NS, Schubert J, et al. The complement inhibitor eculizumab in paroxysmal nocturnal hemoglobinuria. N Engl J Med . 2006 Sep 21;355(12):1233-43.

Blood cells

Review Date: 3/22/2007
Reviewed By: Corey Cutler, M.D., M.P.H., F.R.C.P.C, Department of Medical Oncology, Dana-Farber Cancer Institute; Instructor in Medicine, Harvard Medical School, Boston, MA. Review provided by VeriMed Healthcare Network.

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 the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. 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 process . A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2007 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Home > Medical Reference > Encyclopedia (English)