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Related to polydactylism: polydactyly, argyria, Supernumerary digit


The condition of having supernumerary fingers or toes.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



the presence of extra digits on the hand or foot. The most common congenital developmental anomaly, polydactyly includes such anomalies as doubling of the ungual phalanx or the presence of small digitiform cutaneous appendages. It occurs most commonly in the form of six digits, usually located on a single extremity; no more than 12 or 13 digits on one extremity have been observed. The extra digit is usually located on the inner or outer margin of the hand, and the majority of extra digits are underdeveloped. Polydactyly is corrected surgically.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
According to the proud daddy, his family had a history of polydactylism and he himself had the non-functioning nubs of sixth fingers removed as a child.
Although supernumerary digits appeared normally developed and functional, others have observed skeletal, arterial, or muscular abnormalities in polydactylism cases for humans (Nelson, 1963; Hootnick et al., 1983, 1991; Rivera et al., 1999; Theodorou et al., 2003) and bats (Koford and Krutzsch, 1948; Jennings, 1958; Caire and Thies, 1988).
In humans, polydactylism is hereditary; however, it is not expressed in all offspring (i.e., variable penetrance; Wilson, 1896; Radhakrishna et al., 1997; Zhao, 2002; Galjaard, 2003).
Meanwhile, the order of birth defects in Xi'an City was consistent with the Chinese national data, namely CHD, polydactylism, cleft lip, NTDs, and hydrocephalus.
Polydactylism - being born with an extra finger or toe - is unusual, but it is even more rare for someone to have spare functional digits on both hands and feet.