Color Vision Deficiency Syndrome

1
Color Vision Deficiency Syndrome

• Patrick Grafton-Cardwell
• Period 5
• Biology (H)
• Genetic Disease Project

2
Red-Green Colorblindness

• Anomalous- 6 of white males. Desaturated greens.

• Protanomalous- one sixth of anomalous people.
  Reds wavelengths are darkened.
• Deuteranomalous- five sixths of anomalous people.
  Usually unaware of condition because of limited
  deficiency.

• Red and Green Blindness- 2 of white males.
  Complete inability to see red or green hues.
  Only shades of gray because of a lack of 1 cone
  of vision out of 3.

3
Yellow-Blue Colorblindness

• The person with yellow- blue colorblindness is
  missing one cone of vision and sees the world in
  shades of red, green, and gray.
• This is usually caused by a disease of the retina
  or the development of a cataract, and is very
  rare.
• It is found even more rarely caused by unknown
  hereditary conditions.

4
Monochromatism

• Typical- poor visual acuity, involuntary eyeball
  movements, hypersensitive to light.
• Atypical- normal visual acuity, only loss of
  color vision.
• Like yellow-blue colorblindness, monochromatism
  is extremely rare, and is inherited through
  unknown hereditary conditions and can be caused
  by an eye disease.

5
Genetics

• Mode of inheritance- Red-green color deficiencies
  are carried on the x chromosomes and therefore
  are usually expressed in men.
• Genetic therapy and ethical considerations are
  not needed outside of making sure that the
  diseased person knows of their disease and takes
  precautions in public situations such as driving.

6
Tests and Screening

• The picture on the left can be seen by anyone,
  while in the right hand picture, the 45 is
  invisible to the red-green colorblind individual.

Popular Isihara Colorblind Test.
7
Pedigree
XY
XX
XX
XX
XY
XX
XY
XY
XY
XY
XX
XX
XY
XY
XY
XX
XX
XX
XX
XX
Red letter50/50 chance
Tan boxcolorblind
Black letternormal
Blue letterdisease
Green boxno effects
8
References

• www.toledo-bend.com/colorblind/Isihara
• www.askjeeves.com - various sites.
• Encyclopedia Americana Volume 7, 1997 version.