GCB Masthead
X-linked Mental Retardation Research We have developed a strategy of using human X chromosome-specific cDNA microarrays to identify genes responsible for X-linked mental retardation (XLMR). This approach is designed to detect mutations that result in a change in the abundance of mRNA due to mechanisms such as promoter mutations, gene deletions or duplications, and nonsense or frameshift mutations associated with nonsense mediated mRNA decay. Patients enrolled in the study will receive a comprehensive evaluation in clinical genetics, imaging, and neurobehavioral testing at KKI and the Johns Hopkins Hospital. Involved in the program are investigators at KKI and the Johns Hopkins University School of Medicine’s Department of Pediatrics and Institute of Genetic Medicine and collaborators at the Greenwood Genetic Center, South Carolina.

Research Projects

Gene Expression and Genetic Mental Retardation

We are using modern scientific (molecular) methods to study how genes function in boys with various forms of genetic developmental disabilities, including Down syndrome, Fragile X syndrome, and X-linked mental retardation. With these methods, we hope to uncover molecular defects that are common to several of these conditions, as well as to learn how genes involved in learning, reasoning and memory work in children who have difficulties in these areas. In particular, this study looks at the molecular abnormalities in boys with learning problems of unknown cause and their possible similarities with those in boys with known developmental disabilities.

Funded by the General Clinical Research Center (NIH) of the Johns Hopkins Medical Institutions.

To participate in this study please see our Appointments page.

Faculty Involved

Robert M. Gray, Ph.D.
Michael V. Johnston, M.D.
Walter E. Kaufmann, M.D.,
Paul Lipkin, M.D.
Bruce Shapiro, M.D.
Tao Wang, M.D., Ph.D.


Wang T, Zhang L, Obie C, Mousses S, Trent J, Valle D (2002). Identification of genes responsible for X linked mental retardation using a human X chromosome specific cDNA microarray. American Journal of Human Genetics, 71:188.

X-Linked Mental Retardation Resources

See Family Resources: X-Linked Mental Retardation