{"id":"750eeeab-cbee-53f0-bb70-1894a524bc17","stable_key":"911fb3c7-8cc3-5667-b677-5682fab67648:histidine-uroc-human-loss","predicate":"supports","statement":"A girl with urocanic aciduria carried UROC1 L70P/R450C variants; expression and activity studies supported impaired enzyme function.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"468c2906-911f-5d86-bf8b-a7bbbe61f649","mechanism_event_label":"A block at the second enzyme allowed an upstream metabolite to accumulate.","subject":{"id":"18666f2a-c8d6-5bcd-b3f4-f615272be7fb","slug":"uroc1","display_name":"Human urocanate hydratase / UROC1","entity_type_key":"protein"},"object":{"id":"174b8bc4-5ae3-51de-8cb0-9c994c61dd4c","slug":"human-urocanate-clearance","display_name":"Urocanate handling in human UROC1-associated aciduria","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"468c2906-911f-5d86-bf8b-a7bbbe61f649","stable_key":"911fb3c7-8cc3-5667-b677-5682fab67648:histidine-uroc-human-loss-event","event_type":"observed_relationship","label":"A block at the second enzyme allowed an upstream metabolite to accumulate.","description":"A girl with urocanic aciduria carried UROC1 L70P/R450C variants; 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unverified.","entity":null},{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Single human case plus variant expression, enzyme assays and computational interpretation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"The biochemical association is stronger than attribution of every neurological feature in a single patient.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Histidine collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"histidine","display_name":"L-Histidine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"A block at the second enzyme allowed an upstream metabolite to accumulate.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Mutations in the urocanase gene UROC1 are associated with urocanic aciduria. · 2009 · https://pubmed.ncbi.nlm.nih.gov/19304569/ · DOI 10.1136/jmg.2008.060632","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"trigger_kind","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; 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