A Phenotypic Variant of Knobloch Syndrome

Knobloch syndrome (KNO) is a rare autosomal recessive condition caused by pathogenic mutations in the COL18A1 gene. It is characterized by high myopia, vitreoretinal degeneration, retinal detachment and midline encephalocoele or midline occipital bone defect. We report a case of KNO confirmed by direct sequence analysis of the COL18A1 gene with typical ocular features, and previously unreported systemic features: occipital hair tuft with transient CSF leak and bilateral renal abnormalities. This case illustrates a new phenotypic variant of this syndrome.