Extensive analysis of the FMR-1 gene and the fragile X mutation site in human Xq27.3 is proposed. This gene is likely to be involved in the phenotypic features of fragile X syndrome, the most common form of inherited mental retardation in humans, with a frequency in boys of approximately 1/1200. Analysis of the spectrum of mutations in fragile X families will provide insight into the very unusual mutational and genetic mechanisms in this peculiar region of the X chromosome. Analysis of the FMR-1 gene and its RNA and protein products will allow determination of its role in normal development. The consequences of defects in this gene and their role in generation of mental retardation will be studied. Understanding the basis of the fragile X phenotype will provide insight into potential therapies, and into the nature of other mental deficiencies.
The specific aims of the study are: 1) Characterization of the fragile X mutation site in genomic DNA from patients and other family members; 2) Characterization of the FMR-1 gene located at the fragile X site by definition of its structure, isolation of cDNA representing its mRNA, development of antisera specific to its protein product, and use of these tools to study its expression and presence in tissues from normal and fragile X humans as well as mice at various stages of development; 3) Isolation of the murine equivalent of the FMR-1 gene, characterization of its expression and of the region of the mouse X chromosome for the presence of the peculiar CGG repeat sequence found in humans; 4) Production of a mouse model of fragile X syndrome by gene targeting of the FMR-1 gene in embryonic stem cells and creation of chimeric animals derived from the mutant ES cells; once established, the mouse models will be extensively studied for phenotypic features similar to human fragile X syndrome; 5) Study of the fragile X region for additional genes, and characterization of these for their role (if any) in the syndrome; 6) Identification of other sites in the human genome with long stretches of the CGG repeat sequence, and study of their locations relative to other fragile sites; 7) Analysis of the FMR-1 gene for its role in other, non-fragile X related, mental deficits by mutation detection methods. Characterization of the fragile X mutation and its associated gene will lead to improved diagnosis and provide the capacity to design therapies for this common form of inherited mental retardation. Analysis of the gene should also provide insight into brain function and mechanisms of retardation.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD029256-02
Application #
3330729
Study Section
Mammalian Genetics Study Section (MGN)
Project Start
1992-04-01
Project End
1997-03-31
Budget Start
1993-04-01
Budget End
1994-03-31
Support Year
2
Fiscal Year
1993
Total Cost
Indirect Cost
Name
Baylor College of Medicine
Department
Type
Schools of Medicine
DUNS #
074615394
City
Houston
State
TX
Country
United States
Zip Code
77030
Mientjes, E J; Nieuwenhuizen, I; Kirkpatrick, L et al. (2006) The generation of a conditional Fmr1 knock out mouse model to study Fmrp function in vivo. Neurobiol Dis 21:549-55
Matsuura, Tohru; Fang, Ping; Pearson, Christopher E et al. (2006) Interruptions in the expanded ATTCT repeat of spinocerebellar ataxia type 10: repeat purity as a disease modifier? Am J Hum Genet 78:125-9
Spencer, Corinne M; Serysheva, Ekaterina; Yuva-Paylor, Lisa A et al. (2006) Exaggerated behavioral phenotypes in Fmr1/Fxr2 double knockout mice reveal a functional genetic interaction between Fragile X-related proteins. Hum Mol Genet 15:1984-94
Nishijima, Ichiko; Yamagata, Takanori; Spencer, Corinne M et al. (2006) Secretin receptor-deficient mice exhibit impaired synaptic plasticity and social behavior. Hum Mol Genet 15:3241-50
Mientjes, Edwin J; Willemsen, Rob; Kirkpatrick, Laura L et al. (2004) Fxr1 knockout mice show a striated muscle phenotype: implications for Fxr1p function in vivo. Hum Mol Genet 13:1291-302
Wang, Qing; Gu, Yanghong; Ferguson, James M et al. (2003) Cytogenetic analysis of obsessive-compulsive disorder (OCD): identification of a FRAXE fragile site. Am J Med Genet A 118A:25-8
Gu, Y; Nelson, D L (2003) FMR2 function: insight from a mouse knockout model. Cytogenet Genome Res 100:129-39
Gu, Yanghong; McIlwain, Kellie L; Weeber, Edwin J et al. (2002) Impaired conditioned fear and enhanced long-term potentiation in Fmr2 knock-out mice. J Neurosci 22:2753-63
Morales, Joannella; Hiesinger, P Robin; Schroeder, Andrew J et al. (2002) Drosophila fragile X protein, DFXR, regulates neuronal morphology and function in the brain. Neuron 34:961-72
Peier, Andrea M; Nelson, David L (2002) Instability of a premutation-sized CGG repeat in FMR1 YAC transgenic mice. Genomics 80:423-32

Showing the most recent 10 out of 33 publications