Ectrodactyly: The congenital absence of all or part of one or more fingers or toes.
The term ectrodactyly has been applied to a variety of malformations of the fingers or toes. It is probably best reserved for:
- transverse terminal aphalangia (absence of the last bone in the finger or toe),
- adactylia (total absence of a finger or toes), or
- acheiria (total absence of one or both hands).
Cases of ectrodactyly defined in this way are usually sporadic (with no family history of this malformation). As a rule, one hand is involved and the feet are not affected. Congenital constriction rings ("amniotic bands") are sometimes associated with the malformation.
The hereditary condition called split-hand/split-foot malformation and sometimes called lobster-claw deformity is also termed ectrodactyly, as does another hereditary disorder called the EEC syndrome. (EEC stands for ectrodactyly, ectodermal dysplasia, and facial cleft.)
The word ectrodactyly is derived from the Greek ektroma (abortion) and daktylos (finger) = literally, abortion (of a) finger.