Ophthalmic findings in the Greek isolate of Cohen syndrome

A high frequency of the Cohen syndrome has been observed in a Greek island with 2,000 inhabitants and a high degree of inbreeding. All patients were homozygous for a COH1, exon 6-16 deletion suggesting a founder effect. We present the results of their first systematic ophthalmologic assessment. Myopia and chorioretinal atrophy were present in all patients of this cohort. Yet, in contrast to all groups previously reported, the majority presented with corneal changes, independently from age, gender, and family history. A pair of sisters, aged 11 and 15 years old, presented with bilateral keratoconus. More frequently (86%) than in any other ethnic group, Greek patients had cataracts that were bilateral and often graded as high as 3, even at a young age. As a whole, the ophthalmic phenotype of the Greek isolate of Cohen syndrome is characterized by the involvement of both the posterior and the anterior eye segment, bilaterally, in the majority of cases (93%). Greek Cohen patients that share a founder mutation are at a higher risk of developing blindness in respect to those of other ethnicities and genotypes. This study highlighted the need for pachymetry measurement as a means of surveillance and prediction of the visual impairment frequently observed.