About NICHD - Organization - CDBPM
Mental Retardation and Developmental Disabilities (MRDD) Branch

The MRDD Branch sponsors research and research training aimed at preventing and ameliorating mental retardation and related developmental disabilities. The program involves a full range of research interests, including etiology, pathophysiology, screening, prevention, treatment, and epidemiology. Biomedical, behavioral, and biobehavioral research in these areas is encouraged. The Branch also administers the Mental Retardation Research Centers Program, a network of regional centers developed for research on mental retardation and related aspects of human development. In addition, two brain and tissue banks for MRDD, and mouse models for cytogenetic disorders are supported, through contracts, by the Branch and serve as research resources for the scientific community.

Biomedical Research in Mental Retardation

Genetics and Genetic Disorders--Genetic or genetically influenced conditions are among the leading causes of organically-based mental retardation. Down syndrome and Fragile X syndrome, both involving major chromosomal defects, are of particular research interest, as are single gene defects like phenylketonuria and conditions of polygenic origin, such as neural tube defects and autism.

In addition, genetic disorders of amino acid, carbohydrate, lipid, lysosomal enzymes, purine, and micronutrient (trace metal) metabolism that impact on brain function are of major concern. The development of animal models for understanding pathophysiology, functional deficits, and evaluating therapeutic approaches, including gene therapy, is encouraged. Related studies of behavioral genetics and genetic counseling are also supported.

Molecular Biology And Molecular Genetics--Basic knowledge of the structure and organization of the human genome is essential if the basic molecular defects of conditions that are associated with mental retardation and other forms of developmental disabilities are to be understood. Eventually, such knowledge will contribute to the development of non-invasive or non-destructive methods of primary prevention. Projects dealing with cloning, mapping and organization of genes, and gene transfer into cells, mammalian embryos, and whole animals are encouraged.

Developmental Neurobiology--Major areas that merit research attention include the pathway of differentiation followed by CNS cells; axon outgrowth and target recognition; hormonal and other factors that influence neuronal development, differentiation, and survival; neuroplasticity; factors that contribute to neuronal cell death or degeneration; and neuronal transplantation.

Toxicology and Environmental Factors--Studies of brain development and function have well established the damaging effects of environmental exposure to lead, mercury, and other toxins. Alcohol consumption during pregnancy--when it results in fetal alcohol syndrome--has emerged as one of the leading causes of mental retardation. Research studies and surveillance of these and other agents, such as anticonvulsant and neuroleptic drugs, infection (especially the effects of HIV/AIDS on brain development), and trauma, are needed.

Diagnosis of Mental Retardation--The effort to develop and refine screening methods is essential to prevention and therapy. Emphasis is placed on studies concerned with the early diagnosis of conditions leading to mental retardation. Prenatal diagnostic techniques are of particular interest, as is research on diagnosis of co-morbid conditions in persons with mental retardation and other developmental disorders.

Pathophysiology of Mental Retardation--The Branch sponsors studies to identify the mechanisms of action of the various factors leading to mental retardation and other developmental disabilities. Studies on how a disorder produces its clinical manifestations are directly relevant to its eventual prevention and treatment. The Branch is interested in studies on developmental, neurobiological, morphological, histological, and ultrastructural aspects of the central nervous system, as well as sensory defects and their relation to learning and development.

Epidemiology of Mental Retardation--The Branch supports studies dealing with the identification of persons and population groups at risk for mental retardation and other developmental disabilities. Monitoring the frequency of abnormal genes is a prerequisite to understanding actions that may be taken to modify genetic disease. Studies on genetic susceptibilities and differences are encouraged, along with research to track long-term effects of interventions currently in practice.

Prevention and Amelioration--Gene mapping activities and application of recombinant DNA methods allow isolation of a variety of highly specific human genes. Further advances may lead to new treatments for genetic disorders.

The Branch is interested in development of less invasive techniques for prenatal diagnosis, improved methods of fetal therapy, and development of new biological agents, including vaccines.

Behavioral and Social Science Research in Mental Retardation

Early Identification and Interventions for Infants and Young Children at Risk for Mental Retardation--Intervention studies can identify the processes that lead to meaningful, persistent behavioral and/or developmental gains in persons with diagnosed mental retardation or developmental disabilities or those at risk for disability. This includes studies of the basic mechanisms underlying simple and complex learning, environmental influences on outcome, technological means of achieving desired outcomes, and the development and testing of pharmacological interventions.

Learning, Cognition and Memory in Mental Retardation and Developmental Disabilities--The Branch supports neuroanatomic, neurophysiologic, structural and functional imaging, and neuropsychologic studies of the processes involved. Studies of attention, executive function, working memory, problem solving, and self-awareness are especially encouraged. Also needed is research on the effect of teratogens, such as parental alcohol or drug use on cognitive and behavioral development. Elucidation of critical periods in development across the lifespan is needed.

Family and Community Relationships in Mental Retardation and Developmental Disabilities--Because of the national movement to provide home and family care rather than institutionalization for persons with mental retardation or other developmental disabilities, research on family and community variables is of special interest. Research on the processes of mutual influence between persons with mental retardation or other developmental disabilities and other members of their families or communities is encouraged. Studies of racial and ethnic influences on family adaptation and community acceptance and on differential access to health care are needed.

Communication and Language in Mental Retardation and Developmental Disabilities--The impact of motor and sensory limitations on communicative ability in mental retardation and other developmental disabilities needs to be addressed. Research on verbal and nonverbal communication is of major interest. Studies of precursors of language and of the transition from prelinguistic to linguistic communication are of special interest. Research is needed on the development of nonverbal communication and on the communicative functions of aberrant behavior.

Social and Effective Development in Mental Retardation and Developmental Disabilities--Recent advances in understanding the neurobiology of social and emotional behavior make this an important area for research. Human and animal studies are needed of the psychobiological and behavioral factors and processes that influence social and emotional development and expression in mental retardation and other developmental disorders. Treatment studies are also needed.

Self-Injurious Behavior--A significant percentage of people with mental retardation exhibit some form of SIB, which often leads to social isolation and restrictive treatments. SIB is among the most damaging of all behavior problems exhibited by people with mental retardation, autism, and related developmental disorders. There is an urgent need for studies into the pathophysiology and behavioral deficits associated with SIB and other repetitive behaviors (including animal models), and into the development of therapeutic strategies.

Autism--Autism is a complex neurodevelopmental disability affecting communication, social functioning, and adaptive behavior. Human and animal research including genetic, neuroanatomic, neurophysiologic, immunologic, neurochemical, and neuropsychologic studies are needed to elucidate the etiology and pathophysiology of this disorder. Research on early diagnosis and identification of co-morbid conditions is also encouraged as are studies of effective behavioral and psychopharmacologic interventions. To learn more about the NICHD's efforts in autism research, visit the NICHD Autism Web site.

CONTACT INFORMATION:

Mary Lou Oster-Granite
Chief, MRDD Branch
Address:
6100 Executive Boulevard
Room 4B09G, MSC 7510
Bethesda, MD 20892-7510
Phone: (301) 496-1383
Fax: 301-496-3791
Email: granitem@mail.nih.gov