trichoodontoonychial dysplasia (Monarch Disease Ontology term MONDO_0010153) is a rare ectodermal dysplasia syndrome characterized by severe generalized hypotrichosis, parietal alopecia, secondary anodontia resulting from enamel hypoplasia, onychodystrophy, bone deficiency in the frontoparietal region and skin manifestations (incl. nevus pigmentosus, papules, ephelides, palmoplantar keratosis, supernumerary nipples, abnormal dermatoglyphics). There have been no further descriptions in the literature since 1983. Also known as: trichoodontoonychial dysplasia with bone deficiency in frontoparietal region.