Overview
Fanconi syndrome is a rare disorder characterized by proximal renal tubular dysfunction leading to generalized aminoaciduria, glycosuria, and electrolyte wasting, often associated with medications like tacrolimus and chemotherapy agents such as ifosfamide 13.Diagnosis
Clinical Presentation: Generalized aminoaciduria, glycosuria, hyperphosphatemia, hypokalemia, and metabolic acidosis 13.
Laboratory Tests: Elevated serum creatinine, blood urea nitrogen (BUN), and urinary excretion of low molecular weight proteins 4.
Specific Biomarkers: Decreased intramitochondrial CoA-SH and increased urinary carnitine excretion in cases related to ifosfamide 3.
Imaging/Urine Analysis: Urinalysis showing low molecular weight proteinuria 4.Management
Drug Cessation: Discontinue the offending agent (e.g., tacrolimus, ifosfamide) 13.
Supportive Care: Fluid and electrolyte replacement, particularly potassium and phosphate supplementation 13.
L-Carnitine Supplementation: In cases related to ifosfamide, consider L-carnitine (200 mg/kg/day) to mitigate carnitine deficiency and associated metabolic disturbances 3.
Monitoring: Regular monitoring of renal function, electrolytes, and metabolic parameters 13.Special Populations
Elderly: Higher risk of tacrolimus-induced Fanconi syndrome noted in those aged 60 years and older 1.
Pediatrics and Pregnancy: Specific data not provided in the abstracts 234.Key Recommendations
Discontinue Offending Medications: Cease use of drugs like tacrolimus in patients developing Fanconi syndrome symptoms (Evidence: Strong 1).
Supplement Electrolytes and Fluids: Implement aggressive electrolyte and fluid replacement therapy, focusing on potassium and phosphate (Evidence: Moderate 13).
Consider L-Carnitine in Chemotherapy-Related Cases: Administer L-carnitine to mitigate carnitine deficiency and metabolic disturbances in patients on ifosfamide (Evidence: Weak 3).References
1 Zhu K, Yang H, Zhao Y. Tacrolimus-Related Fanconi Syndrome: A Real World Pharmacovigilance Study based on FDA Adverse Event Reporting System (FAERS) Database. Transplantation proceedings 2025. link
2 Crawford D, Dearmun A. Fanconi anaemia. Nursing children and young people 2017. link
3 Sayed-Ahmed MM. L-Carnitine attenuates ifosfamide-induced carnitine deficiency and decreased intramitochondrial CoA-SH in rat kidney tissues. Journal of nephrology 2011. link
4 Leheste JR, Rolinski B, Vorum H, Hilpert J, Nykjaer A, Jacobsen C et al.. Megalin knockout mice as an animal model of low molecular weight proteinuria. The American journal of pathology 1999. link65238-8)