Purchase this article with an account.
N. B. Stover, P. J. Francis, K. M. Trzupek, M. Kramer, R. G. Weleber, B. R. Olsen; Detailed Electrophysiological and Phenotypic Analysis of Knobloch Syndrome. Invest. Ophthalmol. Vis. Sci. 2007;48(13):1306.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Knobloch syndrome (MIM 267750) is an autosomal recessive disorder characterized by high myopia, vitreoretinal degeneration with significant risk for retinal detachment, and congenital occipital defects. In this article, we present the long-term follow-up and detailed electrophysiological analysis of a sibling pair with Knobloch syndrome who carry a novel mutation in the COL18A1 gene.
Two siblings were clinically evaluated over the course of several years with dilated fundus examination and photography, visual field testing, and electroretinography. DNA sequencing of the COL18A1 gene was performed.
Ophthalmic findings included vitreoretinal degeneration characterized by depigmented, mottled retinal pigment epithelium with intraretinal pigment migration, anomalous appearing optic discs, and the anterior chamber defects of iris illumination and Kruckenberg's spindle. Electroretinography in both siblings demonstrated subnormal cone and rod responses with prolonged rod and cone implicit times. A novel COL18A1 heterozygous mutation was identified in both siblings.
The ophthalmic findings described here further define what is currently known about the ocular phenotype of Knobloch syndrome. To the best of our knowledge, this is the first reported case of detailed electrophysiology in this syndrome, made possible as neither patient has experienced detached retinas.
This PDF is available to Subscribers Only