View clinical trials related to Mental Retardation.
Filter by:The purpose of this research is to study a new way to test for chromosome abnormalities. Chromosomes are strands of DNA (the genetic material in the cell nucleus) that are made up of genes-the units of heredity. Chromosome abnormalities are usually investigated by staining the chromosomes with a dye (Giemsa stain) and examining them under a microscope. This method can detect many duplications and deletions of pieces of chromosomes and is very accurate in diagnosing certain abnormalities. It is not useful, however, for identifying very small abnormalities. This study will evaluate the accuracy of a test method using 24 different dyes for finding small chromosome abnormalities. Children and adults with various chromosome abnormalities may be eligible for this study, including, for example, people with developmental delay or mental retardation, abnormal growth features or growth retardation, and certain behavioral disorders. Participants will be evaluated in the clinic over a 1- to 3-day period, depending on their symptoms. All participants will be examined by a genetics specialist and will have a physical examination and possibly X-rays, computerized tomography (CT) scans, magnetic resonance imaging (MRI), ultrasound studies and medical photography. Blood will be drawn for chromosome testing-about 3 tablespoons from adults and 1 to 3 teaspoons from children. When the test results are available, participants will return to the clinic for follow-up evaluation and review of the test findings. The genetic and medical evaluations, along with their implications, will be discussed.
The purpose of this study is to improve the understanding of the genetic causes of specific neurologic and psychiatric disorders. The study will focus on conditions of mental retardation, childhood onset schizophrenia, attention deficit hyperactivity disorder (ADHD), atypical psychosis of childhood, and bipolar affective disorder. The study addresses the belief that there may be several genes contributing to the illness. Researchers intend to use several molecular genetic techniques in order to identify the areas of chromosomes containing genes responsible for the development of these disorders. Patients will be selected to participate in this study based on an early age of onset of their condition as well as the severity of the illness and the frequency of the illness among family members. Researchers will collect DNA samples from patients as well as affected and unaffected family members of each patient. The DNA samples collected will be analyzed for a variety of genetic abnormalities including; triplet repeat expansions, chromosome rearrangements, and polymorphisms.