Rapp–Hodgkin syndrome was formerly thought to be a unique autosomal dominant disorder due to a P63 gene mutation. However, it was recently shown to the same disease as Hay–Wells syndrome.[1]
^Clements SE, Techanukul T, Holden ST, et al. (September 2010). "Rapp–Hodgkin and Hay–Wells ectodermal dysplasia syndromes represent a variable spectrum of the same genetic disorder". Br. J. Dermatol. 163 (3): 624–9. doi:10.1111/j.1365-2133.2010.09859.x. PMID20491771. S2CID44866051.