EPOS

European Paediatric Ophthalmological Society

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A PDE6C mutation in an autosomal recessive rod monochromacy

PERDOMO TRUJILLO YAUMARA¹, PELLETIER VALERIE¹, GRAU TANJA², DOLLFUS HELENE¹, WISSINGER BERND², KOHL SUSANNE^2
1Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO) et Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, Strasbourg, Fr, ²Molecular Genetic Laboratory, Institute for Ophthalmic Research, Department for Ophthalmology, University Clinics Tübingen, Germany.

Introduction:Rod monochromacy is an autosomal recessive congenital and stationary ocular disorder. Clinically it is characterized by severe photophobia under daylight conditions and nystagmus. Visual acuity is strongly reduced and color discrimination is impossible. In ERG recordings, rod function is normal, but cone function is absent or strongly reduced. It is a genetic dysfunction of all three types of cones. Three genes have been described to be responsible for rod monochromacy, CNGA3, CNGB3 and GNAT2. Methods:Herein we show a consanguineous family that carries a novel homozygous mutation c.1682_1683insA/c.1682_1683insA in PDE6C recently identified by the group in Tübingen as causative in this condition. Results:PDE6C encodes the cone-specific cGMP phosphodiesterase α' subunit, a key component in the phototransduction cascade in cone cells. Conclusion:The mutation described here is to date unique for this family.