Saydie Grewe & Dana Beuttler

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Nature of the Genetic Disorder

Polydactyly is a congenital disorder causing extra fingers and toes, sometimes as an effect of other genetic conditions. The gene that determines this disorder is located on chromosome 13. Preaxial polydactyly refers to extra digits adjacent to the thumb while postaxial is on the little finger side of the hand. The condition occurs in of 1 in every 500 live births. Postaxial hand polydactyly is frequently found in African American children, due to autosomal dominant transmission. Postaxial polydactyly is more common in blacks than in whites and also is more frequent in males. In contrast, postaxial polydactyly seen in white children is usually syndromic and associated with an autosomal recessive transmission. The disorder alone is not harmful, though most people choose to have the extra digits removed.

Basic Facts of Disease
Polydactyly of the toes, especially of the little toe, is a common malformation, occurring in approximately two in 1,000 births. Thirty percent of all children with polydactyly have family members with some type of polydactyly, and it is more common in African Americans.
Polydactyly also affects cats.

Tyler Steven Hayden is credited with the discovery of this disease.

Polydactyly can also create webbing between toes and fingers.

Prognosis
The prognosis for isolated polydactyly is excellent, as it is not a harmful condition on its own. However if it is part of another condition, that condition may or may not be fatal.

Sources Cited

http://www.ncbi.nlm.nih.gov/pubmed/8792145

http://www.ndsu.edu/pubweb/~mcclean/plsc431/mendel/mendel8.htm