The Neurogenetics Branch (NGB) within the National Institute of Neurological Disorders and Stroke (NINDS) is conducting a study to evaluate and provide genetic diagnosis to participants with various diagnosed and undiagnosed neurological conditions. OBJECTIVES: The primary objective of this protocol is to provide a resource of participants for enrollment into new research protocols throughout the NGB and other NIH laboratories. Evaluating and diagnosing participants will allow the NGB specialists to maintain their expertise and gain additional knowledge of the course of various neurological disorders. The information obtained will allow for the evaluation and diagnosis of the studied neurological diseases. This understanding may lead to ideas for future protocols. In some cases, blood or other biologic samples (including urine, saliva, or a cheek (buccal) swab) will be obtained for future laboratory studies. STUDY POPULATION The number of participants to be enrolled will be set to 3,500 participants with neurological diseases and their unaffected relatives. DESIGN: This is an observational diagnostic study of multiple neurological diseases and their pathophysiology. OUTCOME MEASURES: No formal outcomes will be measured; however the clinical assessments of enrolled participants can be used to characterize the disease manifestations. In addition, DNA samples obtained may be used to identify and verify causative mutations as well as identify novel genes, which may help establish pathogenic mechanisms and genotype-phenotype correlations.
- Participants include those with inherited neurological conditions based on the training and research needs of the Neurogenetics Branch program. There is no logical limit; however the total number of participants that can be enrolled in the protocol will be restricted. No more than 3,500 participants with either diagnosed or undiagnosed neurological conditions and their unaffected relatives will be enrolled in this evaluation and diagnostic protocol. INCLUSION CRITERIA: Participants will be eligible if they: - Have either a known or suspected, inherited neurological disease, OR are an unaffected relative (first-, second-, third, or higher degree relative) of a participant with a genetic neurological disease. - Have the ability to understand and sign an informed consent or have a parent/legal guardian to do so if they are minor children or a legal guardian to provide consent for adults without consent capacity. - Aged 2 years and above. EXCLUSION CRITERIA: Participants will not be eligible if they: -Have a systemic disease that compromises the ability to provide adequate neurologic examination or diagnosis.An example of this would be a contagious disease that would compromise our ability to do an adequate neurological exam.