Missense mutations in TCF8 cause late-onset Fuchs corneal dystrophy and interact with FCD4 on chromosome 9p.
Fuchs corneal dystrophy (FCD) is a degenerative genetic disorder of the corneal endothelium that represents one of the most common causes of corneal transplantation in the United States. Despite its high prevalence (4% over the age of 40), the underlying genetic basis of FCD is largely unknown. Here we report missense mutations in TCF8, a transcription factor whose haploinsufficiency causes posterior polymorphous corneal dystrophy (PPCD), in a cohort of late-onset FCD patients. In contrast to PPCD-causing mutations, all of which are null, FCD-associated mutations encode rare missense changes suggested to cause loss of function by an in vivo complementation assay. Importantly, segregation of a recurring p.Q840P mutation in a large, multigenerational FCD pedigree showed this allele to be sufficient but not necessary for pathogenesis. Execution of a genome-wide scan conditioned for the presence of the 840P allele identified an additional late-onset FCD locus on chromosome 9p, whereas haplotype analysis indicated that the presence of the TCF8 allele and the disease haplotype on 9p leads to a severe FCD manifestation with poor prognosis. Our data suggest that PPCD and FCD are allelic variants of the same disease continuum and that genetic interaction between genes that cause corneal dystrophies can modulate the expressivity of the phenotype.
Riazuddin
S Amer
SA
McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Zaghloul
Norann A
NA
Al-Saif
Amr
A
Davey
Lisa
L
Diplas
Bill H
BH
Meadows
Danielle N
DN
Eghrari
Allen O
AO
Minear
Mollie A
MA
Li
Yi-Ju
YJ
Klintworth
Gordon K
GK
Afshari
Natalie
N
Gregory
Simon G
SG
Gottsch
John D
JD
Katsanis
Nicholas
N
D000328:Adult; D017668:Age of Onset; D000368:Aged; D000483:Alleles; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics*; D003317:Corneal Dystrophies, Hereditary / Q000235:genetics*; D004252:DNA Mutational Analysis; D005260:Female; D005642:Fuchs' Endothelial Dystrophy / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D014157:Transcription Factors / Q000235:genetics*; D000071799:Zinc Finger E-box-Binding Homeobox 1
D018398:Homeodomain Proteins; D014157:Transcription Factors; C486307:ZEB1 protein, human; D000071799:Zinc Finger E-box-Binding Homeobox 1