has material basis in germline mutation in UROD inherited porphyria UROD-related inherited porphyria https://github.com/monarch-initiative/mondo/issues/5128 https://github.com/monarch-initiative/mondo/issues/9703 MONDO:0100498 GARD:0026251 Porphyria caused by monoallelic and biallelic variants in UROD and presenting as a spectrum of disease (a semidominant inheritance pattern). Additionally, environmental factors almost always play a role in the disease. Monoallelic variants when exacerbated by environmental factors can result in episodic adult onset of photosensitivity. Biallelic variants that reduce WT enzyme activity <20% cause childhood onset of photosensitivity and sometimes liver damage. UROD-related porphyria