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WikiProject Medicine / Medical genetics (Rated B-class, Mid-importance)
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WikiProject class rating[edit]

This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 16:23, 10 November 2007 (UTC)

Sixth Symptom[edit]

In regards to this passage:

"A sixth symptom associated with achromatopsia/dychromatopsia is seldom reported. Many sufferers are unaware of the three-dimensional aspect of their visual system. They frequently fail to observe any of the stereographic features of a scene."

I have added a [citation needed] on this. I am a complete achromat and am perfectly aware of my three-dimensional visual aspect. The use of the phrase "stereographic" leads me to believe that the author is basing this "sixth symptom" off of the fact that achromats cannot see "stereographic illusions" such as those pictures you stare at where your eyes cross and then you see the statue of liberty or something. Those illusions use COLOR to do what they do, therefore this is not a failure to observe the 3-dimensional, but a failure to see color which is already a known and primary symptom of Achromatopsia. So, any "3D vision tests" using color-based "3D illusions" would be incapable of determining an achromat's ability to distinguish 3-dimensional aspects of vision.

I have not removed the paragraph due to the fact that my reasoning against it, laid out here, constitutes original research. However I would very much like to see the author's source for this statement as it may very well be original research (or a guess) as well. --Lord Galen (talk) 07:38, 24 May 2009 (UTC)

After more than 4 years, I have now removed this paragraph. I can find absolutely no evidence whatsoever to suggest that this statement about Achromats is correct. If the author would like it included, they will need to cite a source. Lord Galen (talk) 08:49, 5 August 2013 (UTC)

Achromatopsia :O[edit]

"Achromatopsia :O" Is the ":O" a smiley, or an identification of the disorder type? —Preceding unsigned comment added by PrinceNaveen1000 (talkcontribs) 05:26, 20 June 2009 (UTC)

That was vandalism from January. Thanks for pointing it out. --Dpryan (talk) 05:39, 20 June 2009 (UTC)

Cerebral (acquired) variation[edit]

Cerebral achromatopsia should be pointed out in the early stages of the introduction, not half way down the page.

Feel free to add it in. --Dpryan (talk) 18:32, 9 October 2009 (UTC)

Not sex-linked?[edit]

Anyone that is a little bit familiar with "regular" color blindness knows that it's a lot more common in males than in females. However, from what I understand, rod monochromacy should be as frequent in females as it is in males since it has nothing to do with the X chromosome (blue monochromacy should be more frequent in males, but it's apparently a lot rarer).
Shouldn't the article mention this: that contrary to regular color blindness, achromatopsia occurs in females as frequently as it occurs in males?
Masorick (talk) 04:04, 6 April 2012 (UTC)

  • I can give you a personal example. My mother had achromotopsia with all four classic symptoms: lack of colour distinction (achromatopia), poor visual acuity (amlyopia; in her case, best corrected vision was 20/200 in one eye, 20/400 in the other), "day blindness" (hemeralopia), and nystagmus (in her case, with one eye oscillating at a faster rate than the other eye). But only the central field of her vision was affected. Her peripheral vision was 20/20 *without* correction.
  • And I have perfectly normal colour vision. This is because achromatopsia and colour deficiency (aka colour blindness) are caused by completely different sets of genes; and whereas achromatopsia can be either inherited (genetic) or acquired (non-genetic), colour deficiency can *only* be genetic.
  • More specifically, the genes that cause blue-yellow and red-green colour deficiency are carried on the X chromosome. Because women have two X chromosomes, a woman must inherit the pertinent gene(s) from both her mother and father to have colour deficiency. That means her father will be colour deficient (because he has only one X chromosome) but her mother need only be a carrier of the gene(s) on just one of her X chromosomes.
  • Conversely, the son of a woman who has colour deficiency cannot avoid having colour deficiency because whichever X chromosome he inherits from his mother, he is going to inherit a gene or genes for colour deficiency - because he only has *one* X chromosome. If his mother does *not* have colour deficiency but is a carrier of one of the genes, he will still be colour deficient if he inherits the X chromosome that carries that gene, whereas *she* will have perfectly normal colour vision.
  • In the case of achromatopsia, both parents can have perfect colour vision and the child can still have defective colour vision (which was true in my mother's case) - because achromatopsia is a completely different problem from colour deficiency.

Do Not Merge This Article![edit]

This article should NOT be merged with the article on monochromacy. It is a completely different subject.

CAUTION: Do not confuse "acromatopia" (no 's') with achromatopsia (with an 's').

Achromatopia or colour deficiency is just one of the symptoms of achromatopsia. The other classic and invariable symptoms of achromatopsia are amblyopia, hemeralopia and nystagmus. Photophobia can also be expressed if the hemeralopia is severe.

If you do not have all four classic symptoms, you do not have achromatopsia.

Monochromacy, on the other hand, only deals with colour deficiency. It is one of the three types of colour deficiency. The other two types of blue-yellow colour deficiency and red-green colour deficiency. Monochromacy exists when someone has both blue-yellow and red-green colour deficiency.

The genes that cause blue-yellow colour deficiency and red-green colour deficiency are carried on the X chromosome. Because men only have one X chromosome, they will be colour deficient if their X chromosome carries the pertinent gene(s). Women, however, have *two* X chromosomes so they must inherit the gene(s) from *both* their parents.


1. A mother can carry a gene for colour deficiency without being colour deficient herself. 2. The daughter of a mother who *is* colour deficient usually will *NOT* be colour deficient (because she would need to get the same gene from her father as from her mother). 3. The son of a mother who is colour deficient *always* will be colour deficient, because whichever X chromosome he inherits from his mother, it is going to be carrying a gene for colour deficiency. 4. The son of a mother with *achromatopsia,* on the other hand, will NOT usually inherit the syndrome from his mother, because genetic achromotopsia is not caused by genes carried on the X chromasome. 5. A person with colour deficiency usually does NOT have amblyopia or hemeralopia, and almost never has nystagmus. They might not be able to see colours but the rest of their vision will usually be normal.

The achromatopia that happens as a symptom of achromatopsia, however, has NOTHING to do with either blue-yellow or red-green colour deficiency. Unlike normal colour deficiency, achromotopsia, 1) need not be caused by genetics and, 2) when it is genetic, it's not caused by the same genes.

Rather, the colour deficiency that is one symptom of achromatopsia involves the ability of the cone cells to receive and/or process light of any kind; with the result the rod cells become saturated, which causes the hemeralopia. 2601:645:C300:16DD:6DA2:295C:2C60:D470 (talk) 11:54, 18 November 2015 (UTC)

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