ZEB1 loss-of-function (LoF) alleles are known to cause a rare autosomal dominant disorder-posterior polymorphous corneal dystrophy type 3 (PPCD3). To date, 50 pathogenic LoF variants have been identified as disease-causing and familial studies have indicated that the PPCD3 phenotype is penetrant in approximately 95% of carriers. In this study, we interrogated in-house exomes (n = 3616) and genomes (n = 88) for the presence of putative heterozygous LoF variants in ZEB1. Next, we performed detailed phenotyping in a father and his son who carried a novel LoF c.1279C>T; p.(Glu427*) variant in ZEB1 (NM_030751.6) absent from the gnomAD v.2.1.1 dataset. Ocular examination of the two subjects did not show any abnormalities characteristic of PPCD3. GnomAD (n = 141,456 subjects) was also interrogated for LoF ZEB1 variants, notably 8 distinct heterozygous changes presumed to lead to ZEB1 haploinsufficiency, not reported to be associated with PPCD3, have been identified. The NM_030751.6 transcript has a pLI score ≥ 0.99, indicating extreme intolerance to haploinsufficiency. In conclusion, ZEB1 LoF variants are present in a general population at an extremely low frequency. As PPCD3 can be asymptomatic, the true penetrance of ZEB1 LoF variants remains currently unknown but is likely to be lower than estimated by the familial led approaches adopted to date.

2nd Department of Medicine Department of Cardiovascular Medicine 1st Faculty of Medicine Charles University and General University Hospital Prague U Nemocnice 2 128 08 Prague Czech Republic

Department of Ophthalmology 1st Faculty of Medicine Charles University and General University Hospital Prague U Nemocnice 2 128 08 Prague Czech Republic

Department of Paediatrics and Inherited Metabolic Disorders 1st Faculty of Medicine Charles University and General University Hospital Prague Ke Karlovu 2 128 08 Prague Czech Republic

Department of Radiology 1st Faculty of Medicine Charles University and General University Hospital Prague Katerinska 30 128 08 Prague Czech Republic

UCL Institute of Ophthalmology University College London London EC1V 9EL UK

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Krachmer J.H. Posterior polymorphous corneal dystrophy: A disease characterized by epithelial-like endothelial cells which influence management and prognosis. Trans. Am. Ophthalmol. Soc. 1985;83:413–475. PubMed PMC

Liskova P., Palos M., Hardcastle A.J., Vincent A.L. Further genetic and clinical insights of posterior polymorphous corneal dystrophy 3. JAMA Ophthalmol. 2013;131:1296–1303. doi: 10.1001/jamaophthalmol.2013.405. PubMed DOI

Liskova P., Dudakova L., Evans C.J., Rojas Lopez K.E., Pontikos N., Athanasiou D., Jama H., Sach J., Skalicka P., Stranecky V., et al. Ectopic GRHL2 Expression Due to Non-coding Mutations Promotes Cell State Transition and Causes Posterior Polymorphous Corneal Dystrophy 4. Am. J. Hum. Genet. 2018;102:447–459. doi: 10.1016/j.ajhg.2018.02.002. PubMed DOI PMC

Cieply B., Farris J., Denvir J., Ford H.L., Frisch S.M. Epithelial-mesenchymal transition and tumor suppression are controlled by a reciprocal feedback loop between ZEB1 and Grainyhead-like-2. Cancer Res. 2013;73:6299–6309. doi: 10.1158/0008-5472.CAN-12-4082. PubMed DOI PMC

Hong T., Watanabe K., Ta C.H., Villarreal-Ponce A., Nie Q., Dai X. An Ovol2-Zeb1 Mutual Inhibitory Circuit Governs Bidirectional and Multi-step Transition between Epithelial and Mesenchymal States. PLoS Comput. Biol. 2015;11:e1004569. doi: 10.1371/journal.pcbi.1004569. PubMed DOI PMC

Plygawko A.T., Kan S., Campbell K. Epithelial-mesenchymal plasticity: Emerging parallels between tissue morphogenesis and cancer metastasis. Philos. Trans. R Soc. Lond. B Biol. Sci. 2020;375:20200087. doi: 10.1098/rstb.2020.0087. PubMed DOI PMC

Davidson A.E., Liskova P., Evans C.J., Dudakova L., Noskova L., Pontikos N., Hartmanova H., Hodanova K., Stranecky V., Kozmik Z., et al. Autosomal-Dominant Corneal Endothelial Dystrophies CHED1 and PPCD1 Are Allelic Disorders Caused by Non-coding Mutations in the Promoter of OVOL2. Am. J. Hum. Genet. 2016;98:75–89. doi: 10.1016/j.ajhg.2015.11.018. PubMed DOI PMC

Krafchak C.M., Pawar H., Moroi S.E., Sugar A., Lichter P.R., Mackey D.A., Mian S., Nairus T., Elner V., Schteingart M.T., et al. Mutations in TCF8 cause posterior polymorphous corneal dystrophy and ectopic expression of COL4A3 by corneal endothelial cells. Am. J. Hum. Genet. 2005;77:694–708. doi: 10.1086/497348. PubMed DOI PMC

Dudakova L., Evans C.J., Pontikos N., Hafford-Tear N.J., Malinka F., Skalicka P., Horinek A., Munier F.L., Voide N., Studeny P., et al. The utility of massively parallel sequencing for posterior polymorphous corneal dystrophy type 3 molecular diagnosis. Exp. Eye Res. 2019;182:160–166. doi: 10.1016/j.exer.2019.03.002. PubMed DOI

Cunnusamy K., Bowman C.B., Beebe W., Gong X., Hogan R.N., Mootha V.V. Congenital Corneal Endothelial Dystrophies Resulting from Novel De Novo Mutations. Cornea. 2016;35:281–285. doi: 10.1097/ICO.0000000000000670. PubMed DOI PMC

Liskova P., Evans C.J., Davidson A.E., Zaliova M., Dudakova L., Trkova M., Stranecky V., Carnt N., Plagnol V., Vincent A.V., et al. Heterozygous deletions at the ZEB1 locus verify haploinsufficiency as the mechanism of disease for posterior polymorphous corneal dystrophy type 3. Eur. J. Hum. Genet. 2016;24:985–991. doi: 10.1038/ejhg.2015.232. PubMed DOI PMC

Liskova P., Filipec M., Merjava S., Jirsova K., Tuft S.J. Variable ocular phenotypes of posterior polymorphous corneal dystrophy caused by mutations in the ZEB1 gene. Ophthalmic Genet. 2010;31:230–234. doi: 10.3109/13816810.2010.518577. PubMed DOI

Jang M.S., Roldan A.N., Frausto R.F., Aldave A.J. Posterior polymorphous corneal dystrophy 3 is associated with agenesis and hypoplasia of the corpus callosum. Vis. Res. 2014;100:88–92. doi: 10.1016/j.visres.2014.04.007. PubMed DOI PMC

Chaudhry A., Chung B.H., Stavropoulos D.J., Araya M.P., Ali A., Heon E., Chitayat D. Agenesis of the corpus callosum, developmental delay, autism spectrum disorder, facial dysmorphism, and posterior polymorphous corneal dystrophy associated with ZEB1 gene deletion. Am. J. Med. Genet. A. 2017;173:2467–2471. doi: 10.1002/ajmg.a.38321. PubMed DOI

Collins R.L., Brand H., Karczewski K.J., Zhao X., Alfoldi J., Francioli L.C., Khera A.V., Lowther C., Gauthier L.D., Wang H., et al. A structural variation reference for medical and population genetics. Nature. 2020;581:444–451. doi: 10.1038/s41586-020-2287-8. PubMed DOI PMC

Galgauskas S., Norvydaite D., Krasauskaite D., Stech S., Asoklis R.S. Age-related changes in corneal thickness and endothelial characteristics. Clin. Interv. Aging. 2013;8:1445–1450. doi: 10.2147/CIA.S51693. PubMed DOI PMC

Zoega G.M., Fujisawa A., Sasaki H., Kubota A., Sasaki K., Kitagawa K., Jonasson F. Prevalence and risk factors for cornea guttata in the Reykjavik Eye Study. Ophthalmology. 2006;113:565–569. doi: 10.1016/j.ophtha.2005.12.014. PubMed DOI

Higa A., Sakai H., Sawaguchi S., Iwase A., Tomidokoro A., Amano S., Araie M. Prevalence of and risk factors for cornea guttata in a population-based study in a southwestern island of Japan: The Kumejima study. Arch. Ophthalmol. 2011;129:332–336. doi: 10.1001/archophthalmol.2010.372. PubMed DOI

Lek M., Karczewski K.J., Minikel E.V., Samocha K.E., Banks E., Fennell T., O’Donnell-Luria A.H., Ware J.S., Hill A.J., Cummings B.B., et al. Analysis of protein-coding genetic variation in 60,706 humans. Nature. 2016;536:285–291. doi: 10.1038/nature19057. PubMed DOI PMC

Karczewski K.J., Francioli L.C., Tiao G., Cummings B.B., Alfoldi J., Wang Q., Collins R.L., Laricchia K.M., Ganna A., Birnbaum D.P., et al. The mutational constraint spectrum quantified from variation in 141,456 humans. Nature. 2020;581:434–443. doi: 10.1038/s41586-020-2308-7. PubMed DOI PMC

Evans C.J., Liskova P., Dudakova L., Hrabcikova P., Horinek A., Jirsova K., Filipec M., Hardcastle A.J., Davidson A.E., Tuft S.J. Identification of six novel mutations in ZEB1 and description of the associated phenotypes in patients with posterior polymorphous corneal dystrophy 3. Ann. Hum. Genet. 2015;79:1–9. doi: 10.1111/ahg.12090. PubMed DOI

Qin L., Wang J., Tian X., Yu H., Truong C., Mitchell J.J., Wierenga K.J., Craigen W.J., Zhang V.W., Wong L.C. Detection and Quantification of Mosaic Mutations in Disease Genes by Next-Generation Sequencing. J. Mol. Diagn. 2016;18:446–453. doi: 10.1016/j.jmoldx.2016.01.002. PubMed DOI

Palmer E.E., Mowat D. Agenesis of the corpus callosum: A clinical approach to diagnosis. Am. J. Med. Genet. C Semin. Med. Genet. 2014;166C:184–197. doi: 10.1002/ajmg.c.31405. PubMed DOI

Liskova P., Tuft S.J., Gwilliam R., Ebenezer N.D., Jirsova K., Prescott Q., Martincova R., Pretorius M., Sinclair N., Boase D.L., et al. Novel mutations in the ZEB1 gene identified in Czech and British patients with posterior polymorphous corneal dystrophy. Hum. Mutat. 2007;28:638. doi: 10.1002/humu.9495. PubMed DOI PMC

Ziegler A., Colin E., Goudenège D., Bonneau D. A spanshot of some pLI score pitfalls. Hum. Mutat. 2019;40:839–841. PubMed

Genotype-Phenotype Correlations in Corneal Dystrophies: Advances in Molecular Genetics and Therapeutic Insights