Clinical features of achromatopsia in Swedish patients with defined genotypes

  title={Clinical features of achromatopsia in Swedish patients with defined genotypes},
  author={Louise Eksandh and Susanne Kohl and Bernd Wissinger},
  journal={Ophthalmic Genetics},
  pages={109 - 120}
Purpose: To describe the clinical phenotype, with emphasis on the electrophysiological findings, of patients with autosomal recessive rod monochromacy (RM) and defined mutations in the CNGA3 / CNGB3 genes. Methods: RM patients from eight different families were included in the study. Their genotypes were determined by DNA sequencing and/or RFLP analysis of PCR-amplified genomic segments of the CNGA3 and CNGB3 genes. For comparison, we investigated one patient with blue-cone monochromacy (BCM… 

Genotypes and phenotypes of genes associated with achromatopsia: A reference for clinical genetic testing

Genotype–phenotype analysis of six achromatopsia-related genes will be useful in drafting guidelines for the clinical genetic diagnostic application for the investigated genes, and PPVs in the six genes were identified in various inherited retinal degeneration diseases.

Progressive cone dystrophy associated with mutation in CNGB3.

PURPOSE To determine the molecular basis for phenotypic variability in a three-generation consanguineous family containing a single individual with complete achromatopsia and three individuals with

CNGB3 mutations account for 50% of all cases with autosomal recessive achromatopsia

CNGB3/ACHM3 locus on chromosome 8q21 is the major locus for achromatopsia in patients of European origin or descent, and mutations in the CNGB3 gene are responsible for approximately 50% of all patients with achrom atopsia.

CNGA3 mutations in two United Arab Emirates families with achromatopsia

Achromatopsia in these two United Arab Emirates families results from two different mutations in CNGA3, demonstrating a complex molecular pathology in this large family.

[Molecular genetic findings in patients with congenital cone dysfunction. Mutations in the CNGA3, CNGB3, or GNAT2 genes].

In patients with congenital cone dysfunction without cone function in the ERG, an analysis of the CNGA3, CNGB3, or GNAT2 gene is advisable; in contrast, patients with residual cone function did not show clear association with mutations in one of the three genes.

Compound heterozygous CNGA3 mutations (R436W, L633P) in a Japanese patient with congenital achromatopsia

To the authors' knowledge, this is the first report of a Japanese complete achromat with CNGA3 mutations, and of any patient with a missense mutation within the CLZ domain, and the outcome suggests low frequency (7%, 1/14) of CN GA3 mutations in Japanese patients.

Achromatopsia caused by novel mutations in both CNGA3 and CNGB3

Current estimates suggest that mutations in CNGB3 account for 40–50% of achromatopsia,14 with mutations inCNGA3 contributing a further 20%.5 There is therefore a significant proportion of patients for whom neither CNGA3 norCNGB3 mutations can be found, and GNAT2 is the third gene to be implicated in achrom atopsia.

Clinical heterogeneity between two Japanese siblings with congenital achromatopsia

Two siblings with congenital achromatopsia are described, who exhibit different ophthalmic phenotypes, and the brother remains hyperopia and has exhibited no specific retinal findings until age 18 years.

CNGB3 achromatopsia with progressive loss of residual cone function and impaired rod-mediated function.

Foveomacular atrophy can occur in CNGB3-affected subjects, and even heterozygous carriers can exhibit maculopathy, and some retain residual function into middle age and then progressively lose even this remnant.

Cone dystrophy phenotype associated with a frameshift mutation (M280fsX291) in the α-subunit of cone specific transducin (GNAT2)

Mutation in the α-subunit of cone specific transducin (GNAT2) is characterised by an infantile onset cone dystrophy, which some affected individuals may show deterioration of visual acuity with time.



Phenotypic expression of juvenile X-linked retinoschisis in Swedish families with different mutations in the XLRS1 gene.

The ERG findings show reduced B-A ratios of dark-adapted recordings and prolonged implicit times of 30-Hz flicker response, which provide a useful clinical marker to confirm the clinical diagnosis of juvenile X-linked retinoschisis.

Electroretinograms in patients with achromatopsia

Measurements of the residual cone b‐wave amplitude responses are of diagnostic and may possibly be of prognostic value when examining children and other members of families with achromatopsia.

Genetic basis of total colourblindness among the Pingelapese islanders

It is demonstrated that both α- and β-subunits of the cGMP-gated channel are essential for phototransduction in all three classes of cones.

Total colourblindness is caused by mutations in the gene encoding the α-subunit of the cone photoreceptor cGMP-gated cation channel

This is the first report of a colour vision disorder caused by defects other than mutations in the cone pigment genes, and implies at least in this instance a common genetic basis for phototransduction in the three different cone photoreceptors of the human retina.

Mutations in the CNGB3 gene encoding the beta-subunit of the cone photoreceptor cGMP-gated channel are responsible for achromatopsia (ACHM3) linked to chromosome 8q21.

Using RT-PCR and RACE, the human cDNA homologue, designated CNGB3, was identified and cloned, which encodes an 809 amino acid polypeptide and was present on 11 of 22 disease chromosomes segregating in families.


There is a question of a syndrome one single symptom of which is the colourblindness, which manifests itself already by photophobia, which causes the patients to tighten their eyelids even in ordinary daylight, and by pronounced undulatory nystagmus.

Molecular genetics of human blue cone monochromacy.

Blue cone monochromacy is a rare X-linked disorder of color vision characterized by the absence of both red and green cone sensitivities. In 12 of 12 families carrying this trait, alterations are

Imaging localized retinal dysfunction with the multifocal electroretinogram.

  • M. BearseE. Sutter
  • Medicine
    Journal of the Optical Society of America. A, Optics, image science, and vision
  • 1996
High sensitivity is demonstrated by mapping a small area that has been partially bleached by a strobe flash in a normal retina and by mapping dysfunctional areas in three patients with different, well-documented retinal pathologies, suggesting that the multifocal electroretinogram has the potential to become a valuable clinical tool.