Fusion of the hands and feet by a thin membrane of skin (scarring) seen in forms of dystrophic epidermolysis bullosa and leading to a 'mitten' hand deformity.
Comment:
Mitten deformity is also referred to as pseudosyndactyly, which should not be confused with true syndactyly (actual and complete fusion of fingers). Antenatally, pseudosyndactyly can be misinterpreted as syndactyly.