Posterior polymorphous corneal dystrophy (PPCD, PPMD, PPD;OMIM # 122000) is a dominantly inherited disorder of the corneal endothelium that is associated with a wide spectrum of clinical features and courses ranging from benign to profound visual loss from corneal swelling with or without associated glaucoma, which develops in approximately 15% of patients. PPCD has been mapped to chromosome 20p11-q11 with a maximum observed LOD score of 5.54 at theta = 0.0 with marker D20S45. Analysis of recombination events in 4 of the 21 affected patients in a single large family revealed that the PPCD gene is located in the 30 cM region between markers D20S98 and D20S108. The objective of this proposal is to identify and characterize the gene(s) responsible for PPCD. This will be accomplished as follows: 1. Better define the minimal candidate genomic region for PPCD. Perform linkage analysis in previously identified and additional new families to continue to fine map the disease locus, narrowing the candidate region, and therefore the number of candidate genes for PPCD. Examine patients with deletions in the candidate gene region of chromosome 20 for clinical features of PPCD, thereby ruling in or out candidate genes in the affected portion of the disease interval. 2. Select and prioritize candidate genes. Determine which genes are expressed in the adult human corneal endothelium. Microarray analyses (normal corneal endothelium, corneal endothelium in PPCD). Serial analysis of gene expression (SAGE). Determine which of the genes found to be expressed in the corneal endothelium map to the candidate gene region (positional approach). Analyze the function of the genes that map to the defined candidate interval, selecting those that may, when mutated, result in the clinical and histopathologic abnormalities seen in PPCD (functional approach). 3. Perform candidate gene screening. Identify sequence variants in the candidate genes. Determine whether identified sequence variants are polymorphisms or mutations. Discovery of the genetic basis of PPCD will provide a definitive means to distinguish it from other conditions with overlapping clinical features and to identify those at increased risk for vision loss from glaucoma as well as provide a greater understanding of the mechanisms of glaucoma development. Additionally, manipulation of this gene may allow researchers to induce the controlled proliferation of corneal endothelial cells in vivo or in vitro, providing an alternative to corneal transplantation for patients with an insufficient number of corneal endothelial cells to maintain corneal clarity, one of the most common indications for corneal transplantation worldwide.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08EY016079-05
Application #
7665326
Study Section
Special Emphasis Panel (ZEY1-VSN (06))
Program Officer
Chin, Hemin R
Project Start
2005-09-30
Project End
2010-08-31
Budget Start
2009-09-01
Budget End
2010-08-31
Support Year
5
Fiscal Year
2009
Total Cost
$166,239
Indirect Cost
Name
University of California Los Angeles
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Yellore, Vivek S; Rayner, Sylvia A; Nguyen, Catherine K et al. (2012) Analysis of the role of ZEB1 in the pathogenesis of posterior polymorphous corneal dystrophy. Invest Ophthalmol Vis Sci 53:273-8
Yellore, Vivek S; Rayner, Sylvia A; Aldave, Anthony J (2011) TGFB1-induced extracellular expression of TGFBIp and inhibition of TGFBIp expression by RNA interference in a human corneal epithelial cell line. Invest Ophthalmol Vis Sci 52:757-63
Lai, Isabella N; Yellore, Vivek S; Rayner, Sylvia A et al. (2010) The utility of next-generation sequencing in the evaluation of the posterior polymorphous corneal dystrophy 1 locus. Mol Vis 16:2829-38
Aldave, Anthony J; Rosenwasser, George O D; Yellore, Vivek S et al. (2010) Linkage of posterior amorphous corneal dystrophy to chromosome 12q21.33 and exclusion of coding region mutations in KERA, LUM, DCN, and EPYC. Invest Ophthalmol Vis Sci 51:4006-12
Aldave, Anthony J; Yellore, Vivek S; Vo, Rosalind C et al. (2009) Exclusion of positional candidate gene coding region mutations in the common posterior polymorphous corneal dystrophy 1 candidate gene interval. Cornea 28:801-7
Kamal, Khairidzan M; Rayner, Sylvia A; Chen, Michael C et al. (2009) Classic lattice corneal dystrophy associated with monoclonal gammopathy after exclusion of a TGFBI mutation. Cornea 28:97-8
Tai, Tak Yee Tania; Damani, Mausam R; Vo, Rosalind et al. (2009) Keratoconus associated with corneal stromal amyloid deposition containing TGFBIp. Cornea 28:589-93
Aldave, Anthony J; Yellore, Vivek S; Sonmez, Baris et al. (2008) A novel variant of combined granular-lattice corneal dystrophy associated with the Met619Lys mutation in the TGFBI gene. Arch Ophthalmol 126:371-7
Weiss, Jayne S; Moller, H U; Lisch, Walter et al. (2008) The IC3D classification of the corneal dystrophies. Cornea 27 Suppl 2:S1-83
Yellore, V S; Sonmez, B; Rayner, S A et al. (2008) A late-onset unilateral variant of lattice corneal dystrophy not associated with a TGFBI mutation. Br J Ophthalmol 92:426-7

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