ectrodactyly

synonyms: cleft hand, lobster-claw deformity, split hand
https://doi.org/10.1351/goldbook.10636

Congenital absence or deficiency of one or more of the central digits of the hand or foot.

Source:
PAC, 2016, 88, 713. (Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)) on page 747 [Terms] [Paper]