Three cases of molecularly confirmed Knobloch syndrome

Background: Knobloch syndrome (OMIM 267750) is a rare autosomal recessive disorder due to genetic defects in the COL18A1 gene. The triad of high myopia, occipital defect, vitreoretinal degeneration has been described as pathognomonic for this condition. Patients with Knobloch syndrome have also extraocular problems as brain and kidney malformations. High genetic and phenotypic variation has been reported in the affected patients.Materials and Methods: Here we provide detailed clinical description of 3 individuals with Knobloch syndrome. Ocular examination and fundus imaging have been performed. Detailed information about systemic conditions has been provided.Results: Mutations in COL18A1 were identified in all three patients. Patient 1 had congenital hip dislocation and patient 2 had renal atrophy, cardiac insufficiency and difficult skin healing.Conclusions: With this report we add to the clinical and genetic knowledge of this rare condition.