polydactyly of a triphalangeal thumb https://github.com/monarch-initiative/mondo/issues/4521 https://github.com/monarch-initiative/mondo/issues/4948 https://www.malacards.org/card/polydactyly_preaxial_ii GARD:0005289 polydactyly, preaxial type II preaxial polydactyly type 2 polydactyly, preaxial II PPD2 polydactyly, preaxial type 2 MEDGEN:357423 triphalangeal thumb, type i icd11.foundation:728781925 SCTID:715710001 DOID:0060986 A form of preaxial polydactyly of fingers, a limb malformation syndrome, that is characterized by the presence of a usually opposable triphalangeal thumb with or without additional duplication of one or more skeletal components of the thumb. The thumb appearance can differ widely in shape (wedge to rectangular) or it can be deviated in the radio-ulnar plane (clinodactyly). PPD2 is also associated with systemic syndromes, including Holt-Oram syndrome and Fanconi anemia. OMIM:174500 UMLS:C1868114 Orphanet:93336 MONDO:0008270 preaxial polydactyly of fingers