This protocol will permit the establishment of a repository of biospecimens from individuals affected with sickle cell disease to identify and evaluate underlying disease mechanism(s), and to facilitate understanding of the pathogenesis and natural history of vaso-occlusive painful crisis and other complications of the disease. Patients will be evaluated with a medical history and physical examination and routine laboratory studies will be obtained as needed to assess diagnosis, disease activity, and disease complications and to monitor for treatment-related responses and toxicities. This protocol may also provide for the continued storage and analysis of clinical and research data, and biospecimens previously obtained from other NIH Institutional Review Board (IRB)-approved protocols with subject consent. Patients eligible for other research protocols will be offered an opportunity to participate in these studies after signed informed consent has been obtained. Apart from such protocols, any medical care or additional tests/investigations recommended or provided to the patient will be consistent with routine standards of practice and will be provided in consultation with the patient s referring physician.
* INCLUSION CRITERIA: * Individuals with known or suspected sickle cell disease * 2 years of age and older * Willing to provide informed consent or appropriate informed consent from parent or legal guardian * Patients seen at sickle outpatient clinics at any one of the participating centers (CNHS or NIH). EXCLUSION CRITERIA: * Patient and/or guardian unable and unwilling to give informed consent or assent. * Patients less than 2 years of age. Individuals with known or suspected sickle cell disease will meet the inclusion criteria to enroll in this protocol and can undergo study activities. However, if the individual is found not to have sickle cell disease after enrollment, they will be removed from the protocol, and their research samples will be discarded but they will be counted toward the study accrual. The study team will notify the individual about their removal from the study and explain the reason for it. Any necessary regulatory reporting will also be completed.