Camptodactyly is a medical condition that causes one or more fingers or toes to be permanently bent. It involves fixed flexion deformity of the proximal interphalangeal joints. Camptodactyly can be caused by a genetic disorder. In that case, it is an autosomal dominant trait that is known for its incomplete genetic expressivity. This means that when a person has the genes for it, the condition may appear in both hands, one, or neither. A linkage scan proposed that the chromosomal locus of camptodactyly was 3q11.2-q13.12. Causes
The specific cause of camptodactyly remains unknown, but there are a few deficiencies that lead to the condition. A deficient lumbrical muscle controlling the flexion of the fingers, and abnormalities of the flexor and extensor tendons.A number of congenital syndromes may also cause camptodactyly:

Jacobsen syndrome
Beals syndrome
Blau syndrome
Freeman–Sheldon syndrome
Cerebrohepatorenal syndrome
Weaver syndrome
Christian syndrome 1
Gordon syndrome
Jacobs arthropathy-camptodactyly syndrome
Lenz microphthalmia syndrome
Marshall–Smith–Weaver syndrome
Oculo-dento-digital syndrome
Tel Hashomer camptodactyly syndrome
Toriello–Carey syndrome
Trisomy 13
Stuve–Wiedemann syndrome
Loeys–Dietz syndrome
Fetal alcohol syndrome
Fryns syndrome
Marfan syndrome
Carnio-carpo-tarsal dysthropy

Genetics
The pattern of inheritance is determined by the phenotypic expression of a gene—which is called expressivity. Camptodactyly can be passed on through generations in various levels of phenotypic expression, which include both or only one hand. This means that the genetic expressivity is incomplete. It can be inherited from either parent. In most of its cases, camptodactyly occurs sporadically, but it has been found in several studies that it is inherited as an autosomal dominant condition. Treatment
If a contracture is less than 30 degrees, it may not interfere with normal functioning. The common treatment is splinting and occupational therapy.
United States
In the United States, under federal anti-discrimination laws such as the Americans with Disabilities Act, color vision deficiencies have not been found to constitute a disability that triggers protection from workplace discrimination. Research
Some tentative evidence finds that color blind people are better at penetrating certain color camouflages. Such findings may give an evolutionary reason for the high rate of red–green color blindness. There is also a study suggesting that people with some types of color blindness can distinguish colors that people with normal color vision are not able to distinguish. In World War II, color blind observers were used to penetrate camouflage.In September 2009, the journal Nature reported that researchers at the University of Washington and University of Florida were able to give trichromatic vision to squirrel monkeys, which normally have only dichromatic vision, using gene therapy.In 2003, a cybernetic device called eyeborg was developed to allow the wearer to hear sounds representing different colors. Achromatopsic artist Neil Harbisson was the first to use such a device in early 2004; the eyeborg allowed him to start painting in color by memorizing the sound corresponding to each color. In 2012, at a TED Conference, Harbisson explained how he could now perceive colors outside the ability of human vision. See also
List of people with color blindness
Motion blindness
Red–green color space
Tetrachromacy
City university test
Color anomia - Ability to see colors, but inability to name colors. Color agnosia - Ability to see colors, but inability to recognize colors. References
Further reading
External links

Color blindness at Curlie
"A Glossary of Color Science."