To report a simultaneous occurrence of 2 rare corneal dystrophies.
A 30-year-old man with a family history of posterior polymorphous corneal dystrophy type 3 (PPCD3) was invited for ophthalmic examination. Sanger sequencing of the coding regions and intron/exon boundaries of disease-associated genes, ZEB1 and UBIAD1, was performed.
The clinical findings suggested co-occurrence of PPCD3 and Schnyder corneal dystrophy in the proband. This dual diagnosis was supported by genetic findings. He was identified to carry a previously reported heterozygous nonsense mutation in ZEB1: c.2157C>G; p.(Tyr719*), and a novel heterozygous missense mutation in UBIAD1: c.569T>C; p.(Ile190Thr). The mother of the proband only carried c.2157C>G in ZEB1, and slit-lamp examination of her corneas showed endothelial lesions characteristic of PPCD3. The sister of the proband carried c.569T>C in UBIAD1 and had corneal crystal deposition in her anterior stroma consistent with the diagnosis of Schnyder corneal dystrophy.
This case illustrates the coincidental occurrence of 2 rare and genetically distinct corneal dystrophies in a single patient. Furthermore, it highlights the need to perform comprehensive phenotyping in combination with appropriate genetic diagnostic testing to achieve an accurate diagnosis.
*Research Unit for Rare Diseases; First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic; First Faculty of Medicine, Charles University, Prague, Czech Republic;
†Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic; and
‡UCL Institute of Ophthalmology, London, United Kingdom.
Correspondence: Petra Liskova, MD, PhD, Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, General University Hospital in Prague and First Faculty of Medicine, Charles University, Ke Karlovu 2, 128 08 Prague, Czech Republic (e-mail: firstname.lastname@example.org).
Supported by GACR 17-12355S. Institutional support was provided by UNCE 204064 and PROGRES Q26 programs of Charles University. P. Skalicka was supported by GAUK 250361/2017 and SVV 260367/2017. A. E. Davidson is a Fight for Sight Early Career Investigator.
The authors have no conflicts of interest to disclose.
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Received December 17, 2018
Received in revised form February 08, 2019
Accepted February 08, 2019