The ectodermal dysplasias (EDs) are a clinically and genetically heterogeneous group of disorders, with X-linked hypohidrotic ectodermal dysplasia (XLHED) being the most common of them. An autosomal recessive form of the disorder exists (ARHED), which is clinically indistinguishable from XLHED, causing identical abnormalities of tooth, hair, and sweat gland development. Clinical molecular testing is not available to distinguish ARHED from XLHED, nor for the identification of carrier females in many families with XLHED. Together with our collaborators, we have successfully identified the gene for XLHED (EDA) and its murine homolog Tabby (Ta). We propose to analyze the spectrum of mutations seen in over 170 families with XLHED, and from these data design an optimal strategy for clinical molecular testing to improve diagnosis. The analysis may also identify essential functional domains within the EDA protein. The Ta and EDA proteins are highly homologous proteins whose function are unknown. Identification of the EDA and Ta genes provides an opportunity to explore the role of these novel proteins in epithelial-mesenchymal signaling and in the development of teeth, hair and eccrine sweat glands. We will begin to define the functions of the Ta/EDA proteins using a number of approaches: analysis of tissue specific and developmental patterns of gene expression, functional analysis of protein isoforms using transgenic mouse technologies, and identification of interacting proteins using the yeast two-hybrid assay. We will also identify the genes associated with the autosomal recessive forms of HED in humans and mice. They are likely to be members of a common developmental pathway that include the EDA/Ta proteins. The overall hypothesis of this proposal is that a continued molecular genetic analysis of the human disorders, X-linked (XLHED) and autosomal recessive (ARHED) hypohidrotic ectodermal dysplasia, and of their murine homologs (Ta, cr, dl) will identify new genes essential for morphogenesis and assist in understanding the function and interactions of their proteins. At the same time, the new knowledge should rapidly result in improved genetic diagnosis and counseling, and may even suggest avenues for future therapies.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE011311-10
Application #
6176696
Study Section
Oral Biology and Medicine Subcommittee 1 (OBM)
Program Officer
Moshell, Alan N
Project Start
1991-07-01
Project End
2003-08-31
Budget Start
2000-09-01
Budget End
2001-08-31
Support Year
10
Fiscal Year
2000
Total Cost
$320,915
Indirect Cost
Name
Oregon Health and Science University
Department
Genetics
Type
Schools of Medicine
DUNS #
009584210
City
Portland
State
OR
Country
United States
Zip Code
97239
Orange, Jordan S; Brodeur, Scott R; Jain, Ashish et al. (2002) Deficient natural killer cell cytotoxicity in patients with IKK-gamma/NEMO mutations. J Clin Invest 109:1501-9
Chen, Y; Molloy, S S; Thomas, L et al. (2001) Mutations within a furin consensus sequence block proteolytic release of ectodysplasin-A and cause X-linked hypohidrotic ectodermal dysplasia. Proc Natl Acad Sci U S A 98:7218-23
Schneider, P; Street, S L; Gaide, O et al. (2001) Mutations leading to X-linked hypohidrotic ectodermal dysplasia affect three major functional domains in the tumor necrosis factor family member ectodysplasin-A. J Biol Chem 276:18819-27
Zonana, J; Elder, M E; Schneider, L C et al. (2000) A novel X-linked disorder of immune deficiency and hypohidrotic ectodermal dysplasia is allelic to incontinentia pigmenti and due to mutations in IKK-gamma (NEMO). Am J Hum Genet 67:1555-62
Kibar, Z; Dube, M P; Powell, J et al. (2000) Clouston hidrotic ectodermal dysplasia (HED): genetic homogeneity, presence of a founder effect in the French Canadian population and fine genetic mapping. Eur J Hum Genet 8:372-80
Monreal, A W; Ferguson, B M; Headon, D J et al. (1999) Mutations in the human homologue of mouse dl cause autosomal recessive and dominant hypohidrotic ectodermal dysplasia. Nat Genet 22:366-9
Ferguson, B M; Thomas, N S; Munoz, F et al. (1998) Scarcity of mutations detected in families with X linked hypohidrotic ectodermal dysplasia: diagnostic implications. J Med Genet 35:112-5
Monreal, A W; Zonana, J; Ferguson, B (1998) Identification of a new splice form of the EDA1 gene permits detection of nearly all X-linked hypohidrotic ectodermal dysplasia mutations. Am J Hum Genet 63:380-9
Taylor, T D; Hayflick, S J; McKinnon, W et al. (1998) Confirmation of linkage of Clouston syndrome (hidrotic ectodermal dysplasia) to 13q11-q12.1 with evidence for multiple independent mutations. J Invest Dermatol 111:83-5
Munoz, F; Lestringant, G; Sybert, V et al. (1997) Definitive evidence for an autosomal recessive form of hypohidrotic ectodermal dysplasia clinically indistinguishable from the more common X-linked disorder. Am J Hum Genet 61:94-100

Showing the most recent 10 out of 12 publications