Hayley Dardick and

Taylor Kiyota

Color blindness is usually inherited and is due to mutations on the X chromosome.

Mutations span from at least nineteen different chromosomes and 56 different genes, though 9 genes on the X chromosome are generally what’s effected.

Inherited color blindness can develop anywhere from birth to adulthood.

Though it’s most commonly inherited due to mutations on the X chromosome there are other mutations and diseases that can cause color blindness.

Color blindness is a recessive gene. This means a male would only need to inherit one

mutated X chromosome to show the disease while a female would need to inherit two mutated X chromosomes to present with color blindness.

Because males only have one X chromosome they are significantly more susceptible to inheriting color blindness.

X Y

X XX XY

X XX XY

25% chance of a color blind male, 25% chance of an

uneffected male, 25% chance of a carrier female and 25%

of an effected daughter

Passing on the disease

•A color blind man with an unaffected woman would result in heterozygous carrier daughters.

•The sons of these parents would not inherit colorblindness because they would receive their father’s healthy Y chromosome, not his mutated X chromosome.

•A colorblind male and a carrier woman has 50 percent chance of passing color blindness on to each of her male children.

•A colorblind male and a carrier or colorblind woman could result in a colorblind daughter if she inherited the mutated X chromosome from each parent.

Types of Color Blindness

Complete Color Blindness

Red-Green Color Blindness

Blue-Yellow Color

Blindness

Achromatopsia is complete inability to see

color. A person with complete color blindness cannot perceive colors even though their eyes can distinguish them.

Those with protanopia, deuteranopia, protanomaly and deuteranomaly or red-green color blindness have trouble distinguishing red from green. This type is sex-linked and the most

common

Those with tritanopia and tritanomaly have trouble with blues and

yellows.

Degrees of Color Blindness There are three types of inherited or congenital color blindness:

monochromacy, dichromacy and anomalous.

Monochromacy is complete color blindness and the lack of ability to distinguish colors. Mhonocramats can only detect variations in brithness. Occurs when two or even all three of the cone pigments are missing. Two types: rod monochromacy and cone monochromacy.

Dichromacy is hereditary and moderately severe. This occurs when one of the cone pigments is missing Three types: protanopia (red appears dark), deuteranopia (green

receptors missing) and tritanopia (complete absense of blue photo receptors)

Anomalous trichromacy is inherited and occurs when one cone pigment is missing. This results in impaired three-dimensional color vision) Three types: protanomaly, deuteranomaly and tritanomaly.

Colors viewed by someone with no form of color blindness or deficiency.

Colors viewed by someone with protanopia.

Colors viewed by someone with deuteranopia.

Colors viewed by someone with tritanopia.

Color blindness in the U.S.

Color blindness is more common in males than female In the United States around

seven percent of males or 10.5 million men are color blind.

In females the rate is much lower. Only .4 percent of females have some type of color blindness.

Males Females

Red-Green (overall)

7 to 10% -

Red-green (Caucasians)

8% -

Red-green (Asians) 5% -

Red-green (Africans) 4% -

Monochromacy - -

Rod Monochromacy .00001% .00001%

Dichromacy 2.4% .03%

Protanopia 1 to 1.3% .02%

Deuteranopia 1 to 1.2% .01%

Tritanopia .001% .03%

Anomalous Trichromacy

6.3% .37%

Protanopia 1.3% .02%

Deuteranopia 5.0% .35%

Tritanopia .01% .01%

DiagnosisDiagnosing color blindness is easy and painless

A series of pictures with colored sports called the Ishihara color test is used to diagnose red-green color blindness. Slightly different colored numbers or symbols are embedded in the

spots. A person with no vision deficiency can identify the number easily,

where someone with who is color blind or has a deficiency can not.

Physical SymptomsBeing color blind does not present with any

physical symptoms.

There is nothing that would alter the life expectancy of someone who was color blind other than the fact they are more prone to accidents Motor accidents in people who are color blind are

common because distinguishing the colors of the lights is more difficult.

TreatmentThere is no cure to correct the vision of

someone who is color blind.

However, contact lenses and filters that help people distinguish different colors more easily have been invented.

The National Eye Institute is researching new ways to treat colorblindness and is ultimately trying to find a cure for it.

Everyday LifePeople who are colorblind have to

alter the way they understand things in order to go about their daily routines.

An example of this is determining whether one’s clothes match each day as they get dressed.

Another example is driving. Colorblind people can drive, but they can’t rely on “green = go, yellow = slow down, or red = stop.” Instead, they have to know the position of the lights/colors . Red on the top, yellow in the middle,

and green on the bottom. So when they see the bottom light lit up, they know to “go.”

Everyday LifeAnother obstacle

colorblind people often face, is reading and understanding graphics or maps.

Our society relies on color fir many reasons. For example, color-coding has become a popular way to show or sort information.

Keys on maps label different roads and paths using different colors. Distinguishing various shades of red and orange on a green surface is more difficult for people who are green-red colorblind.

LimitationsBeing colorblind doesn’t necessarily affect

a person’s quality of life, but there are limitations in some cases

There are certain careers people who are colorblind can not participate in.Pilots are an example of a career people who

are colorblind may not do.Electricians dealing with various colored

wires is another example.A third career is a cook. Identifying if the

meat was cooked could be an issue for someone who is color blind.

Kids with ColorblindnessEveryone is colorblind at birth, though most people

grow out of this. People who are color blind or have a vision deficiency never grow out of this.

Organizations have been founded to educate and help families cope with colorblind children cope with the deficiency. Kids Health:

http://kidshealth.org/kid/talk/qa/color_blind.html

Prevent Blindness America- Children:http://www.preventblindness.org/children/

Children’s Mercy Hospitals and Clinics:http://www.childrensmercy.org/pa/view.aspx?id=742

Will there ever be a cure?

The possibility of a cure being found is high due to our knowledge of this disease.

Colorblindness has actually been cured in some mice and monkeys by injecting the missing genes into their chromosomes.

"Color Blindness." Wikipedia, the Free Encyclopedia. 27 Feb. 2011. Web. 28 Feb. 2011. <http://en.wikipedia.org/wikiColor_blindness#Design_implications_of_color_blindness>.

Flück, Daniel. "Way to Cure Color Blindness?" Colblindor. 27 Mar. 2007. Web.

Lambert, Katie. "Discovery Health "What the Colorblind Can Do"" Discovery Health "Health Guides" 2011. Web. 28 Feb. 2011. <http://health.howstuffworks.com/colorblindness5.htm>.