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(1998). https://pubmed.ncbi.nlm.nih.gov/9486994/ DOI: 10.1056/NEJM199803053381004","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"renal activation machinery modeled in cultured cells","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"trigger_kind","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null}],"evidence":[{"id":"5d2dda89-8e10-53d9-9ba4-21be56009d77","evidence_kind":"source_excerpt","locator":"Lines 482-495","start_line":482,"end_line":495,"excerpt":"### vd-act-cyp27b1-mutations\nAll four homozygous CYP27B1 missense variants identified in four unrelated rickets patients abolished measured 1alpha-hydroxylase activity when expressed in COS-1 cells.\nCondition category: machinery_impairment\nnutrient_topic: Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: An inherited enzyme defect can block the final activation step.\norganism: Homo sapiens proteins in COS-1 cells\ntissue_or_cell_type: renal activation machinery modeled in cultured cells\nexperimental_model: Patient sequencing and heterologous functional assays\nlimitations: Functional loss is experimentally supported; clinical severity cannot be predicted solely from this assay.\nexposure: Four patient-derived variants versus normal enzyme; dose/time not specified in abstract.\ncross_nutrient: false\nevidence_location: Primary abstract, Methods and Results.\nnutrient: Vitamin D2 and D3\n[kitanaka1998] Inactivating mutations in the 25-hydroxyvitamin D3 1alpha-hydroxylase gene in patients with pseudovitamin D-deficiency rickets. 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