Familial vocal fold paralysis can be a life-threatening disorder that can cause difficulty with vocal fold movement for breathing and voice and sometimes for swallowing. Studies are ongoing at the NIH to better understand the pathophysiology and to relate it to the genetic pattern of inheritance. Families are being recruited to participate in these studies and are being provided with further information on the disorder and genetic counseling if desired. Physician referral is requested for affected members of families with vocal fold paralysis of an unknown cause occurring over at least 2 generations. All travel, lodging, examination and counseling costs are covered for both affected and unaffected members of a family. Examinations include: voice, laryngeal, neurological, electrodiagnostic testing, genetic counseling, and radiological studies....