A deformity, dysmorphism, or dysmorphic feature is a major difference in the shape of the body a body part, or a body organ (internal or external) compared to the average shape for the part in question. Deformity may arise from numerous causes:
Irish Mythology includes the Fomorians, who are almost without exception described as being deformed, possessing only one of what most have two of (eyes, arms, legs, etc.) or having larger than normal limbs. Other mythological creatures may have been created due to a deformative syndrome also, for instance, descriptions of mermaids may be related to the symptoms of sirenomelia.
In many cases in which a major deformity is present at birth, it is the result of an underlying condition severe enough that the baby does not survive very long. In some societies, defective babies are abandoned at birth: some are saved by the "kindness of strangers."(See John Boswell.)