Analysis of the posterior polymorphous corneal dystrophy 3 gene, TCF8, in late-onset Fuchs endothelial corneal...

Because the endothelial (posterior) corneal dystrophies share common pathologic features and result from primary endothelial dysfunction, it is possible that a proportion of them could be clinical manifestations of different mutations of the same gene. The aim of our study was to determine whether mutations of the TCF8 gene, recently implicated in posterior polymorphous dystrophy, may also play a role in the development of the more common Fuchs endothelial corneal dystrophy (FECD).

Genomic DNA was extracted from leukocytes of peripheral blood, and the nine exons of the TCF8 gene were PCR amplified and subjected to bidirectional sequencing and analysis. Samples from 74 unrelated Chinese patients (55 women, 19 men) with a diagnosis of late-onset FECD and 93 age- and race-matched controls were studied.

The affected probands ranged in age from 52 to 91 years (mean age, 65.1 years); 8 had familial FECD and 66 had sporadic FECD. The authors found two mutations in the coding region of the TCF8 gene: a novel missense mutation in one patient c.2087A>G in exon 7 (Asn696Ser) and a silent mutation in exon 2 c.192T>C (D64D).

The identification of a novel missense mutation in only one of the patients implied that TCF8 does not play a significant role in the pathogenesis of FECD in this Chinese population.