Novel mutations in the ZEB1 gene identified in Czech and British patients with posterior polymorphous corneal dystrophy.

We describe the search for mutations in six unrelated Czech and four unrelated British families with posterior polymorphous corneal dystrophy (PPCD); a relatively rare eye disorder. Coding exons and intron/exon boundaries of all three genes (VSX1, COL8A2, and ZEB1/TCF8) previously reported to be implicated in the pathogenesis of this disorder were screened by DNA sequencing. Four novel pathogenic mutations were identified in four families; two deletions, one nonsense, and one duplication within exon 7 in the ZEB1 gene located at 10p11.2. We also genotyped the Czech patients to test for a founder haplotype and lack of disease segregation with the 20p11.2 locus we previously described. Although a systematic clinical examination was not performed, our investigation does not support an association between ZEB1 changes and self reported non-ocular anomalies. In the remaining six families no disease causing mutations were identified thereby indicating that as yet unidentified gene(s) are likely to be responsible for PPCD.

Factors affecting the epidemiology of Acanthamoeba keratitis.

Despite being a relatively rare disease in comparison with other forms of infectious keratitis, Acanthamoeba keratitis is a potentially blinding disease. Wide variations in the incidence of Acanthamoeba keratitis have been reported in both developed and developing countries. At the same time that contact lens wear was found to be responsible for the spread of the disease in developed countries, Acanthamoeba keratitis was considered a rare disease in developing countries compared with fungal and bacterial keratitis. In recent decades, the risk of getting Acanthamoeba keratitis has increased because of the increased proportion of contact lens wearers. This article introduces the different factors affecting the epidemiology of Acanthamoeba keratitis worldwide, presents a chronological review of the literature, and shows the progressive spread of Acanthamoeba keratitis in the last two decades in different geographical areas of the world. A detailed comparison of the incidence of the disease as reported in different studies in different countries is made. The impact of contact lenses and other factors, such as hot weather, virulence of Acanthamoeba strains, water sanitation and quality, the occurrence of environmental disasters such as flooding, and the wide environmental presence of Acanthamoeba cysts on the incidence of the disease, are discussed. In addition, the ability of Acanthamoeba cysts to resist different harsh conditions is reviewed.