View clinical trials related to Genetic Variation.
Filter by: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.
Background: - Congenital malformations, sometimes called birth defects, occur because of a difference in early human development. There are many different types of congenital malformations, and some of these can be caused by changes in genetic material. Researchers are interested in studying individuals with these congenital malformations to better understand the causes and the effects of certain congenital malformations. Objectives: - To understand more about what causes congenital malformations that arise in early human development. - To learn if genetic causes can be found to explain why a person has a congenital malformation. Eligibility: - Individuals who have been diagnosed with a congenital malformation. Design: - Participants will be seen at the National Institutes of Health for a series of visits over 3 to 4 days. Participants will be asked to provide copies of past medical records and test results for review, and will be asked questions about pregnancy/prenatal history, birth, newborn, medical, developmental, and family history. - Parents or siblings of participants may also be asked to provide information for research purposes. - Participants may have additional medical evaluations as part of this study, including any of the following tests: - Physical examinations - Other consultations as clinically indicated - Blood samples for genetic testing - Tissue biopsy for genetic testing - Photographs of affected areas, such as front and side views of the face and other body parts that may be involved in a congenital malformation, like the hands and feet. - Other tests as indicated by a specific malformation, such as organ ultrasounds. - No additional invasive testing, testing requiring sedation, or testing involving radiation is planned for this protocol. These tests, if performed, would involve a separate consent....
The aim of the project is to positionally clone susceptibility genes for NIDDM. Patients will be ascertained in Finland from previous health surveys and hospital discharge records. Approximately 400 affected sib pairs will be collected. Families will be chosen who have, at most, one parent with NIDDM no history of IDDM. A clinical examination will be undertaken on family members and blood drawn for DNA isolation. Covariates such as body weight, blood pressure, lipid levels and urinary albumin will also be measured. The unaffected spouse and children of a subset of probands will be invited to undergo a frequently-sampled intravenous glucose tolerance test (FSIGT) to measure parameters of pancreatic function and peripheral insulin resistance (IR). A number of unrelated elderly non-diabetic subjects will also be identified to conduct a population-based association analysis. The FSIGT analysis will be performed in Los Angeles. The DNA will be shipped to Bethesda where a total genomic scan will be performed using semi-automated fluorescence-based genotyping technology. Data from Bethesda, Los Angeles and Finland will be sent to Ann Arbor where parametric and non-parametric methods will be used to analyse both discrete traits such as NIDDM and intermediate traits like IR....