To the editor: The X-Linked Lymphoproliferative Syndrome Registry was recently established and is funded by the National Cancer Institute. We invite referrals of possible cases of the X-linked lymphoproliferative syndrome as well as unusual complications associated with infectious mononucleosis. The following criteria may be used to ascertain whether a patient is a candidate for the registry.
1. Phenotypes (1) of the proliferative types including fatal infectious mononucleosis, immunoblastic sarcoma of B cells, immunodeficiency with hyper IgM after infectious mononucleosis, or American Burkitt lymphoma. Aproliferative phenotypes such as agranulocytosis, aplastic anemia, or acquired hypogammaglobulinemia.
2. The phenotypes of X-linked lymphoproliferative syndrome