Historical aspects of supernumerary anatomical structures in arm and hand

Abstract

After a state of the art in our current research on the applied anatomy of some structures in the human hand, examples of supernumerary structures in lower arm and hand are discussed, by means of their presence during ontogeny and in comparative anatomy. Historical aspects are the common thread. In nonhuman primates and their predecessors, the presence of such supernumerary muscles as the contrahentes muscles and extensor digitorum profundus muscle may be quite normal, but in human anatomy most of these muscle layers disappear during ontogeny. Full persistence, however, may be associated with certain genetic conditions. Another example of this, namely supernumerary digital rays in the hand, better known as the Ellis-van Creveld (EVC) syndrome or postaxial polydactyly, is then discussed. First depicted in 1670, this genetic condition did persist by inheritance, in the offspring of 17th and 18th century Mennonite migrants, fleeing from Switzerland and the Palatinate. Currently described in Amish and Brasilian families, EVC syndrome also occurs in some Western Australian Aboriginal families. By means of palaeography we make plausible that the most probable link with their Swiss and Palinate ancestors via the Dutch Republic could be the following. Some members of the first Mennonite refugee group, who arrived in Holland in April / May 1710 may have joined the crew of the Dutch East India ship “Zuytdorp” during the next year. On 1 August 1711, this vessel set sail from the port of Wielingen in Walcheren, Holland. However, after departing from the Cape of Good Hope on 22 April 1712, she later that year wrecked on the bare rocks of Western Australia’s coast. Descendants of her castaways, who after being helped by local Aboriginals eventually mixed up with them, may subsequently have transmitted the Ellis-van Creveld gene in some Aboriginal families. Certain fragments from oral history may support the palaeographic evidence. Goldblatt J., et al. (1992) Ellis-van Creveld syndrome in a Western Australian Aboriginal