To determine the molecular genetic cause of posterior polymorphous corneal dystrophy (PPCD) in four Czech probands.Methods
Extensive ophthalmological examination including Pentacam and specular microscopy, and direct sequencing of the ZEB1 coding region were performed.Results
Two novel frameshift mutations within ZEB1 were identified; c.2617dup in exon 8 in a 21-year-old female, considered to be most likely de novo in origin, and c.698dup in exon 6 in a 21-year-old male. The first case had mild changes consistent with a PPCD diagnosis and best corrected visual acuity (BCVA) bilaterally was 1.0. The corneal phenotype of the second case was more severe with a BCVA of 0.4 in the right and 0.05 in the left eye. Corneas of both probands were abnormally steep (keratometry readings K1 ≥ 47.4 D and K2 45 ≥ 49.2 D) with increased pachymetry values, but no pattern indicative of keratoconus. Specular microscopy in both patients revealed reduced endothelial cell density (range 1055- 655 per mm2). Both probands had a history of surgery for inguinal hernia; the male patient also reported the presence of hydrocele.Conclusion
Nucleotide changes within the coding region of ZEB1 underlie the pathogenesis of PPCD in 4 out of 23 (17.4%) Czech probands.