TY - JOUR
T1 - Oligocone trichromacy: clinical and molecular genetic investigations
AU - Andersen, Mette K G
AU - Christoffersen, Nynne L B
AU - Sander, Birgit
AU - Edmund, Carsten
AU - Larsen, Michael
AU - Grau, Tanja
AU - Wissinger, Bernd
AU - Kohl, Susanne
AU - Rosenberg, Thomas
PY - 2010/1/1
Y1 - 2010/1/1
N2 - PURPOSE: To describe the phenotype and genotype of patients with a diagnosis of oligocone trichromacy (OT). METHODS: Six unrelated patients had a detailed ophthalmic examination including color vision testing, a Goldmann visual field test, fundus photography, and full-field electroretinography (ffERG). Five patients also underwent multifocal (mf)ERG, autofluorescence recording, and optical coherence tomography (OCT). Genetic analysis included sequencing of all coding regions and flanking introns of CNGA3, CNGB3, GNAT2, KCNV2, and PDE6C. RESULTS: All patients had subnormal visual acuity, a history of congenital nystagmus, and subjectively normal or near-normal color vision; five patients reported photophobia. Clinical examinations revealed largely normal fundi, normal Goldmann visual field results with the IV/4e target, and normal color discrimination or mild color vision deficiency. Electrophysiological investigations showed either complete absence of recordable cone responses or severely reduced amplitudes. All retinal layers were identifiable by OCT, which also showed thinning of the peripheral retina. Genetic analysis revealed two causative CNGB3 mutations in one patient and single heterozygous mutations of unknown significance in CNGB3 and PDE6C in two other patients. CONCLUSIONS: Oligocone trichromacy is a heterogeneous condition with respect to both phenotypic appearance and genetic background. The finding of mutations in genes known to be involved in complete and incomplete achromatopsia supports the notion that some forms of OT is an extreme form of incomplete achromatopsia with preferential loss of peripheral cones.
AB - PURPOSE: To describe the phenotype and genotype of patients with a diagnosis of oligocone trichromacy (OT). METHODS: Six unrelated patients had a detailed ophthalmic examination including color vision testing, a Goldmann visual field test, fundus photography, and full-field electroretinography (ffERG). Five patients also underwent multifocal (mf)ERG, autofluorescence recording, and optical coherence tomography (OCT). Genetic analysis included sequencing of all coding regions and flanking introns of CNGA3, CNGB3, GNAT2, KCNV2, and PDE6C. RESULTS: All patients had subnormal visual acuity, a history of congenital nystagmus, and subjectively normal or near-normal color vision; five patients reported photophobia. Clinical examinations revealed largely normal fundi, normal Goldmann visual field results with the IV/4e target, and normal color discrimination or mild color vision deficiency. Electrophysiological investigations showed either complete absence of recordable cone responses or severely reduced amplitudes. All retinal layers were identifiable by OCT, which also showed thinning of the peripheral retina. Genetic analysis revealed two causative CNGB3 mutations in one patient and single heterozygous mutations of unknown significance in CNGB3 and PDE6C in two other patients. CONCLUSIONS: Oligocone trichromacy is a heterogeneous condition with respect to both phenotypic appearance and genetic background. The finding of mutations in genes known to be involved in complete and incomplete achromatopsia supports the notion that some forms of OT is an extreme form of incomplete achromatopsia with preferential loss of peripheral cones.
KW - Adult
KW - Child
KW - Color Perception Tests
KW - Color Vision
KW - Color Vision Defects
KW - Cyclic Nucleotide Phosphodiesterases, Type 6
KW - Cyclic Nucleotide-Gated Cation Channels
KW - DNA Mutational Analysis
KW - Electroretinography
KW - Eye Diseases, Hereditary
KW - Eye Proteins
KW - Female
KW - Fluorescein Angiography
KW - GTP-Binding Protein alpha Subunit, Gi2
KW - Genotype
KW - Humans
KW - Male
KW - Middle Aged
KW - Nystagmus, Congenital
KW - Phenotype
KW - Polymerase Chain Reaction
KW - Polymorphism, Restriction Fragment Length
KW - Potassium Channels, Voltage-Gated
KW - Retinal Cone Photoreceptor Cells
KW - Retinal Diseases
KW - Tomography, Optical Coherence
KW - Visual Acuity
KW - Visual Fields
U2 - 10.1167/iovs.09-3988
DO - 10.1167/iovs.09-3988
M3 - Journal article
C2 - 19797231
VL - 51
SP - 89
EP - 95
JO - Investigative ophthalmology & visual science
JF - Investigative ophthalmology & visual science
IS - 1
ER -