Inclusion Criteria

- ELIGIBILITY CRITERIA

CAEBV PATIENTS

Study size: up to 150 patients

Sex distribution: male and female

Age range:no minimum nor maximum age

Patients known to have CAEBV and their relatives will be recruited by referrals from
health care providers. The rarity of this disease will markedly limit the number of
patients available to study.

Patient recruitment is irrespective of racial and ethnic group or gender. NIAID
investigators will be available to answer questions and discuss general aspects of CAEBV
and identified genes or modifier genes with participants or their providers.

Eligibility criteria:

To be considered having CAEBV, a patient must have:

1. a severe progressive illness that began at least 6 months ago as a primary EBV
infection, or associated with markedly elevated EBV-specific antibody titers (IgG-VCA
greater than or equal to 1:5,120; EA greater than or equal to 1:640 or EBNA less than
1:2 with other serologies positive) not otherwise explained AND

2. evidence of major organ involvement such as lymphadenitis, hemophagocytosis,
meningoencephalitis, persistent hepatitis, splenomegaly, interstitial pneumonitis,
bone marrow hypoplasia, uveitis AND

3. detection of elevated levels of EBV DNA, RNA or proteins in affected tissues OR
elevated levels of EBV DNA in the peripheral blood AND

Exclusion criteria:

(a) Any other condition that, in the opinion of the investigator, would make the patient
unsuitable for enrollment or could interfere with the patient participating in the study.

RELATIVES OF CAEBV PATIENTS

Study size: up to 150 relatives of CAEBV patients

Age range: 2 years and above

To determine the genetic basis for this syndrome, the evaluation of blood and previously
obtained tissue specimens from healthy relatives of CAEBV patients will serve as controls.
No tissue biopsies will be performed on healthy relatives. We will perform studies on
blood samples from normal relatives.

UNRELATED VOLUNTEERS

Study size: up to 300 persons

Age range: 18 years and above

Panels of anonymous blood samples will be obtained through NIH Clinical Center Blood
Transfusion Medicine to determine if identified genetic changes are mutations or
polymorphisms.