Studies of Children With Metabolic and Other Genetic Disorders

This study will provide medical evaluations for patients with known or suspected metabolic and genetic disorders. It will allow NICHD investigators and trainees experience in diagnosing, managing, and treating patients with metabolic and genetic disorders who may not be eligible for an active NIH research trial. Participants in this protocol will only have tests and procedures used in the standard practice of medicine; there will be no experimental tests or treatments. Patients who are found eligible for an active research protocol will be offered participation in that study. The medical evaluations in this trial may uncover new disease processes that prompt new research initiatives. People of all ages with a suspected or diagnosed genetic or metabolic condition may be eligible for this study. In addition, children with unexplained developmental delay, deafness, dysmorphism, congenital malformations, acidosis, failure to thrive, feeding problems, short stature, birth defects, and other syndromes of unknown cause may qualify. Participants will have a medical history, including a family history, with possible review of previous medical records, and a physical examination. Other procedures may include: * Consultation with medical specialists. * Hearing and/or vision tests. * Imaging studies, such as X-rays, ultrasound and magnetic resonance imaging (MRI). * Blood drawing Blood samples (2 to 4 tablespoons from adults and 1 to 2 tablespoons from children) may be used for routine lab tests, genetic study, and other research purposes. * Cheek swab DNA may be obtained by a cheek swab. A small brush is rubbed against the inside of the cheek to collect some cells. * Skin biopsy Under local anesthetic, a small circle of skin (about 1/8-inch) is removed with a sharp cutting instrument similar to a cookie cutter. * Muscle biopsy Under local anesthetic, a small piece of muscle tissue is removed to aid in diagnosis. Participants will undergo only diagnostic procedures that are