Inclusion Criteria

- INCLUSION CRITERIA:

- Subjects, ages birth to 999 years old, known to have or suspected of having an
inherited disorder of allergic inflammation or mast cell homeostasis or activation,
will be eligible for enrollment. Because of the intensive time and labor required
for research laboratory testing, subjects will be enrolled only if in the opinion of
the investigator (based on discussions with the patient's private physician) there is
a high index of suspicion of a genetic disease of allergic inflammation. Blood
relatives of enrolled subjects will be eligible for enrollment. There will be no
discrimination as to age, gender, race, or disability.

- Subjects must have a health care provider outside of the NIH.

- Subjects/guardians must be willing and able to give informed consent.

- Subjects must agree to have their blood stored for future studies of the immune
system and/or other medical conditions.

- Women will be included in the study, including those who are lactating or may be
pregnant.

- Children will be included in the study.

EXCLUSION CRITERIA:

- The presence of an acquired abnormality of the immune system, such as cytotoxic
chemotherapy or malignancy, may be grounds for possible exclusion if, in the opinion
of the investigator, the presence of such a disease process would interfere with
evaluation.

- Subjects with a history of HIV or evidence of chronic Hepatitis B and/or C infection
will be excluded.