MSD Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

X-Linked Lymphoproliferative Syndrome

(Duncan Syndrome)


James Fernandez

, MD, PhD, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University

Last full review/revision Apr 2021| Content last modified Apr 2021
Click here for the Professional Version

X-linked lymphoproliferative syndrome results from an abnormality in T cells and natural killer cells and results in an abnormal response to Epstein-Barr virus infection.

  • People with X-linked lymphoproliferative syndrome develop a serious, sometimes fatal form of infectious mononucleosis after being infected with Epstein-Barr virus.

  • Doctors diagnose the disorder by genetic testing and sometimes other tests.

  • Stem cell transplantation is necessary for survival and may cure the disorder.

There are two types, which result from different gene mutations but cause similar symptoms.

The second type can cause a rare but serious disorder called hemophagocytic lymphohistiocytosis, which causes immunodeficiency in infants and young children. In hemophagocytic lymphohistiocytosis, too many blood cells in the immune system are activated. The result is widespread inflammation. Sometimes this overactivation is triggered by infectious organisms such as EBV.



  • Blood tests

  • Genetic testing

  • Sometimes bone marrow biopsy

Doctors suspect X-linked lymphoproliferative syndrome in young boys who have severe EBV infection, other characteristic problems, or family members with similar symptoms.

The diagnosis is confirmed by genetic testing. However, genetic testing can take weeks to complete, so doctors may do specialized blood tests, such as flow cytometry (analysis of proteins on the surface of white blood cells), to check for abnormalities in immune cells. Sometimes a bone marrow biopsy Bone Marrow Examination Red blood cells, most white blood cells, and platelets are produced in the bone marrow, the soft fatty tissue inside bone cavities. Sometimes a sample of bone marrow must be examined to determine... read more is done.

Laboratory and imaging tests are done yearly to check for lymphoma and anemia.

Genetic testing is recommended for family members.


  • Stem cell transplantation

About 80% of people who receive a stem cell transplant Stem Cell Transplantation Stem cell transplantation is the removal of stem cells (undifferentiated cells) from a healthy person and their injection into someone who has a serious blood disorder. (See also Overview of... read more survive. Transplantation can cure X-linked lymphoproliferative syndrome if it is done before EBV infection or other disorders become too severe.

Rituximab (a drug that modifies the immune system's activity) can help prevent severe EBV infection before transplantation is done.

More Information

The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Test your knowledge
Transplantation of Other Tissues
Transplantation of tissues, organs, and body parts often requires the use of drugs to suppress the immune system in order to prevent rejection. Which of the following types of transplant requires immunosuppressant drugs? 
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID