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Oligodactyly (from the Ancient Greek ''oligos'' meaning "few" and δάκτυλος ''daktylos'' meaning "finger") is the presence of fewer than five fingers or toes on a hand or foot.〔(NIH website ), citing ''Merriam-Webster's Medical Dictionary''. Accessed February 16, 2010.〕〔(Medical terms Dictionary ). Accessed February 16, 2010〕 It is quite often incorrectly called ''hypodactyly'', but the Greek prefixes hypo- and hyper- are used for continuous scales (e.g. in hypoglycaemia and hypercholesterolemia). This as opposed to discrete or countable scales, where oligo- and poly- should be used (e.g. in oligarchy and polygamy). Oligodactyly is therefore the opposite of polydactyly.〔〔(). Accessed February 16, 2010.〕 Very rare, this medical condition usually has a genetic or familial etiology.〔〔 〕 Oligodactyly is sometimes a sign or symptom of several syndromes including Poland syndrome and Weyer Ulnar Ray Syndrome.〔P D Turnpenny, J C Dean, P Duffty, J A Reid, and P Carter, "Weyers' ulnar ray/oligodactyly syndrome and the association of midline malformations with ulnar ray defects." J Med Genet. 1992 September; 29(9): 659–662. Found at (NIH website ). Accessed last on February 17, 2010.〕 It is a type of Dysmelia. Ectrodactyly is an extreme instance of oligodactyly, involving the absence of one or more central digits of the hand or foot and is also known as split hand/split foot malformation (SHFM). The hands and feet of people with ectrodactyly are often described as "claw-like" and may include only the thumb and one finger (usually either the little finger, ring finger, or a syndactyly of the two) with similar abnormalities of the feet. People with oligodactyly often have full use of the remaining digits and adapt well to their condition. Outside the occasional stare, they are not greatly hindered in their daily activities, if at all.〔 Even those with the most extreme forms are known to engage in tasks that require fine control, such as writing〔 and bootmaking〔 as well as working as a cab driver.〔 Vadoma people of Zimbabwe have a high frequency of oligodactyly.〔(Ripley's believe it or not ) (with photo).〕 ==References== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Oligodactyly」の詳細全文を読む スポンサード リンク
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