Guttmacher syndrome (MONDO_0008301) is an extremely rare syndrome characterized by hypoplastic thumbs and halluces, 5th finger clinobrachydactyly, postaxial polydactyly of the hands, short or uniphalangeal 2nd toes with absent nails and hypospadias. Also known as: preaxial deficiency-postaxial polydactyly-hypospadias syndrome.