Syndactyly type 2 or synpolydactyly (SPD) is a rare congenital distal limb malformation characterized by the combination of syndactyly and polydactyly.

A measured foot length that is more than 2 SD below the mean for a newborn of 27 - 41 weeks gestation, or foot that is less than the 3rd centile for individuals from birth to 16 years of age (objective). Alternatively, a foot that appears disproportionately short (subjective).