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

@article{Kohl1998TotalCI,
  title={Total colourblindness is caused by mutations in the gene encoding the $\alpha$-subunit of the cone photoreceptor cGMP-gated cation channel},
  author={Susanne Kohl and Tim Marx and Ian Giddings and Herbert J{\"a}gle and Samuel G. Jacobson and E Apfelstedt-Sylla and Eberhart Zrenner and Lindsay T. Sharpe and Bernd Wissinger},
  journal={Nature Genetics},
  year={1998},
  volume={19},
  pages={257-259}
}
Total colourblindness (OMIM 216900), also referred to as rod monochromacy (RM) or complete achromatopsia, is a rare, autosomal recessive inherited and congenital disorder characterized by photophobia, reduced visual acuity, nystagmus and the complete inability to discriminate between colours. Electroretinographic recordings show that in RM, rod photoreceptor function is normal, whereas cone photoreceptor responses are absent. The locus for RM has been mapped to chromosome 2q11 (ref. 2), however… 

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

TLDR
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TLDR
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Achromatopsia caused by novel mutations in both CNGA3 and CNGB3

TLDR
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TLDR
Therapeutic supplementation of the wild type transgene may help correct the visual disorders caused by these two mutations, which appear to induce loss of function by impairing the channel cellular trafficking and plasma membrane targeting.

Accessory heterozygous mutations in cone photoreceptor CNGA3 exacerbate CNG channel–associated retinopathy

TLDR
A digenic and triallelic inheritance pattern in a subset of patients with achromatopsia/severe cone dystrophy linked to the CNGB3/p.R403Q mutation is strongly suggested, with important implications for diagnosis, prognosis, and genetic counseling.

A homologous genetic basis of the murine cpfl1 mutant and human achromatopsia linked to mutations in the PDE6C gene

TLDR
It is shown that the spontaneous mouse mutant cpfl1 that features a lack of cone function and rapid degeneration of the cone photoreceptors represents a homologous mouse model for PDE6C associated achromatopsia.

Achromatopsia: the CNGB3 p.T383fsX mutation results from a founder effect and is responsible for the visual phenotype in the original report of uniparental disomy 14

TLDR
The prevalence of mutations in achromatopsia-causing genes in a cohort of 16 families with both clinical and electrophysiologic evidence consistent with autosomal recessive transmission is investigated, concluding that CNGA3 and CNGB3 mutations are responsible for the substantial majority of achrom atopsia.

Achromatopsia as a potential candidate for gene therapy.

TLDR
Using adeno-associated virus (AAV)-mediated gene therapy, it is shown that cone function can be restored in all three models and suggests that human achromatopsia may be a good candidate for corrective gene therapy.

Novel homozygous mutation in the alpha subunit of the rod cGMP gated channel (CNGA1) in two Spanish sibs affected with autosomal recessive retinitis pigmentosa

TLDR
The pathophysiology of RP involves apoptosis of rod cells, and many of the ARRP genes are rod specific, some are only expressed in the retinal pigment epithelium, and none is cone specific.
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TLDR
It is concluded that the absence or paucity of functional cGMP-gated cation channels in the plasma membrane is deleterious to rod photoreceptors and is an uncommon cause of RP.

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TLDR
It is speculated that the rod dysfunction in the patient with congenital stationary night blindness is due to an abnormal, continuous activation of transducin by mutant opsin molecules in photoreceptor outer segments.

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TLDR
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TLDR
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TLDR
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TLDR
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TLDR
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TLDR
The cloning of the cDNA encoding the α‐subunit of the CNG channel of human cone photoreceptors, located on the pericentric band q11.2 of human chromosome 2, is reported here.

Rod and cone photoreceptor cells express distinct genes for cGMP-gated channels