Genetics and Pain Severity in Sickle Cell Disease

Study Summary

Background: \- Pain is the most common symptom of sickle cell disease. Episodes of severe sickle cell pain are known as "crises." High rates of pain crises are associated with a higher risk of early death. Some people with sickle cell disease have many severe pain crises while others experience fewer crises. This difference in pain crisis may be caused by sensitivity to pain. People with high sensitivity to pain may have more pain crises. Many factors, including a person's genetic makeup, determine sensitivity to pain. Comparing genetic information from people with sickle cell disease and healthy volunteers may provide more information on pain and sickle cell disease. Objectives: \- To study genetics and pain sensitivity in sickle cell disease. Eligibility: * African or African American individuals at least 18 years of age with sickle cell disease. * Healthy African or African American volunteers at least 18 years of age. Design: * Participants will be screened with a medical history and physical exam. They will also provide blood and urine samples. * Participants will have the following tests: * Quantitative sensory testing to measure sensitivity to pressure, heat, cold, and mechanical pain. * EndoPat test to measure blood vessel function and reaction. * Questionnaires about mood, evidence of depression, pain, quality of sleep, and sleep disturbances. * Measures of daily pain, whether or not related to sickle cell disease. * After the first visit, those in the study will have monthly study visits for 6 months. The above tests will be repeated at these visits.