Mesoaxial synostotic syndactyly (MSSD) with phalangeal reduction is a novel and distinct form of non-syndromic syndactyly including complete syndactyly of the 3rd and 4th fingers with synostoses of the corresponding metacarpals and associated single phalanges, syndactyly of the 2nd and 3rd toes and 5th finger clinodactyly. The disease is MONDO_0012271 (mesoaxial synostotic syndactyly with phalangeal reduction). Also known as: MSSD, syndactyly type 9, syndactyly, Malik-Percin type.