title: Comprehensive assessment of genetic variants within TCF4 in Fuchs' endothelial corneal dystrophy.
abstract: OBJECTIVE
  The single nucleotide variant (SNV), rs613872, in the transcription factor 4 (TCF4) gene was previously found to be strongly associated (P = 6 × 10(-26)) with Fuchs' endothelial corneal dystrophy (FECD). Subsequently, an intronic expansion of the repeating trinucleotides, TGC, was found to be even more predictive of disease. We performed comprehensive sequencing of the TCF4 gene region in order to identify the best marker for FECD within TCF4 and to identify other novel variants that may be associated with FECD.
  
  
  METHODS
  Leukocyte DNA was isolated from 68 subjects with FECD and 16 unaffected individuals. A custom capture panel was used to isolate the region surrounding the two previously validated markers of FECD. Sequencing of the TCF4 coding region, introns and flanking sequence, spanning 465 kb was performed at >1000× average coverage using the Illumina HiSequation 2000.
  
  
  RESULTS
  TGC expansion (>50 repeats) was present in 46 (68%) FECD-affected subjects and one (6%) normal subject. A total of 1866 variants, including 1540 SNVs, were identified. Only two previously reported SNVs resided in the TCF4 coding region, neither of which segregated with disease. No variant, including TGC expansion, correlated perfectly with disease status. Trinucleotide repeat expansion was a better predictor of disease than any other variant.
  
  
  CONCLUSIONS
  Complete sequencing of the TCF4 genomic region revealed no single causative variant for FECD. The intronic trinucleotide repeat expansion within TCF4 continues to be more strongly associated with FECD than any other genetic variant.
authors.affiliation: Departments of Biochemistry and Molecular Biology , Mayo Clinic, Rochester, Minnesota, United States Medical Genome Facility, Mayo Clinic, Rochester, Minnesota, United States.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Wieben
authors.affiliation: Departments of Biochemistry and Molecular Biology , Mayo Clinic, Rochester, Minnesota, United States.
authors.forename: Ross A
authors.initials: RA
authors.lastname: Aleff
authors.affiliation: Medical Genome Facility, Mayo Clinic, Rochester, Minnesota, United States.
authors.forename: Bruce W
authors.initials: BW
authors.lastname: Eckloff
authors.affiliation: Departments of Health Sciences Research and Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, United States.
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Atkinson
authors.affiliation: Departments of Health Sciences Research and Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, United States.
authors.forename: Saurabh
authors.initials: S
authors.lastname: Baheti
authors.affiliation: Departments of Health Sciences Research and Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, United States.
authors.forename: Sumit
authors.initials: S
authors.lastname: Middha
authors.affiliation: Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States.
authors.forename: William L
authors.initials: WL
authors.lastname: Brown
authors.affiliation: Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States.
authors.forename: Sanjay V
authors.initials: SV
authors.lastname: Patel
authors.affiliation: Departments of Health Sciences Research and Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, United States.
authors.forename: Jean-Pierre A
authors.initials: JP
authors.lastname: Kocher
authors.affiliation: Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States.
authors.forename: Keith H
authors.initials: KH
authors.lastname: Baratz
mesh_terms: D000368:Aged; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics*; D017931:DNA Primers / Q000737:chemistry; D005260:Female; D005642:Fuchs' Endothelial Dystrophy / Q000235:genetics*; D005819:Genetic Markers; D005838:Genotype; D006801:Humans; D007438:Introns / Q000235:genetics; D008297:Male; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D017422:Sequence Analysis, DNA; D000073940:Transcription Factor 4; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D017931:DNA Primers; D005819:Genetic Markers; C532096:TCF4 protein, human; D000073940:Transcription Factor 4; D014157:Transcription Factors
keywords: Fuchs' dystrophy; TCF4; repeat expansion; transcription factor 4; trinucleotide