Monarch Disease Ontology id MONDO_0011884 (hypotrichosis-osteolysis-periodontitis-palmoplantar keratoderma syndrome) is an extremely rare ectodermal dysplasia syndrome characterized by hypotrichosis universalis with mild to severe scarring alopecia, acro-osteolysis, onychogryphosis, thin and tapered fingertips, periodontitis and caries leading to premature teeth loss, linear or reticular palmoplantar keratoderma and erythematous, scaling, psoriasis-like skin lesions on arms and legs. Lingua plicata and ventricular tachycardia have also been observed. Also known as: HOPP syndrome, hypotrichosis-osteolysis-periodontitis-palmoplantar hyperkeratosis syndrome, hypotrichosis-striate palmoplantar hyperkeratosis-acroosteolysis-periodontitis syndrome, hypotrichosis-striate palmoplantar keratoderma-acroosteolysis-periodontitis syndrome.