The exact cause of the condition is unknown. In some cases, close family members may share this condition. In other cases, no other related persons have this condition. The scientific name for the condition is syndactyly, although this term covers both<unk>  fingers and<unk> . Syndactyly occurs when apoptosis or programmed cell death during gestation is absent or incomplete.<unk>  occur most commonly in the following circumstances: * Syndactyly or familial syndactyly * Down syndrome It is also associated with a number of rare conditions, notably: * Aarskog–Scott syndrome * Acrocallosal syndrome * Apert syndrome * Bardet–Biedl syndrome * Carpenter syndrome * Cornelia de Lange syndrome * Edwards syndrome * Jackson–Weiss syndrome * Fetal hydantoin syndrome * Miller syndrome * Pfeiffer syndrome * Smith–Lemli–Opitz syndrome * Timothy syndrome * Ectodermal dysplasia * Klippel–Feil syndrome
Webbed toes
Polydactyly
Clinodactyly
Brachydactyly
Syndactyly
Oligodactyly
Pachydermodactyly
Black heel and palm