Fanconi syndrome (FS) can present with hypophosphatemia, renal glycosuria, hypouricemia and aminoaciduria. Phosphate depletion is the most critical clinical aspect of FS as it leads to osteomalacia. Some patients present with symptoms and signs related to hypophosphatemic osteomalacia (HO). Thus, these patients present with these symptoms and are misdiagnosed. From an investigation of the published literature, HO symptoms are found to be non-specific and were thus misdiagnosed in various centers. The present study describes the case of a a 46-year-old male with FS who suffered from joint pain and was first misdiagnosed. After he was referred to the authors\' hospital, his case was evaluated and following a consideration of the results of this evaluation, he was diagnosed with idiopathic FS with multiple osteoporotic fractures. Furthermore, the present study performs a brief literature review other cases of patients that were misdiagnosed and whose symptoms were later found to be due to HO are also discussed. It is hoped that the present study may increase the awareness of HO among physicians and may help to draw attention to such cases of patients presenting with non-specific symptoms.

This case presentation highlights the need to routinely monitor renal function in patients on Tenofovir Disoproxil Fumarate (TDF) due to its side effect of proximal tubule dysfunction.
UNASSIGNED: This is a case presentation of a 50-year-old African female who had been on a Tenofovir based regimen for 12 years and developed Fanconi syndrome. She recovered after discontinuation of the Tenofovir Disoproxil Fumarate (TDF).

Light-chain proximal tubulopathy (LCPT) is typically characterized by the intracytoplasmic deposition of light chains within the proximal tubular epithelial cells, which is usually classified into crystalline and noncrystalline subgroups. Membranous nephropathy (MN) is a common glomerular disease characterized by diffused subepithelial electron-dense deposits along the capillary loop accompanied by the effacement and microvillus transformation of the foot process. Here, we report a biopsy-confirmed case of a concurrence of LCPT with crystals (κ light chains restricted) and antigen-undetermined MN in a male patient. The patient presented with low-molecular-weight proteinuria, increased serum creatinine levels, and incomplete Fanconi syndrome. To our knowledge, this is the first report of a concurrence of LCPT and independent MN of unknown target antigens, which may enrich our recognition of monoclonal gammopathy of renal significance with synchronous MN.

Wilson\'s disease (WD) is a rare inherited disease due to the mutation of the ATP7B gene, resulting in impaired hepatic copper excretion and its pathological accumulation in various organs such as the liver, the nervous system, or the kidneys. Whereas liver failure and neuropsychiatric disorders are the most common features, less is known about the renal complications. We conducted a review of the literature to define the characteristics and pathophysiology of kidney involvement during WD. This review shed light on strong evidence for direct copper toxicity to renal tubular cells. Excessive tubular copper accumulation might present with various degrees of tubular dysfunction, ranging from mild hydroelectrolytic and acid-base disorders to complete Fanconi syndrome. Proximal and distal renal tubular acidosis also favors development of nephrolithiasis, nephrocalcinosis, and bone metabolism abnormalities. Indirect complications might involve renal hypoperfusion as occurs in hepatorenal or cardiorenal syndrome, but also tubular casts\' formation during acute hemolysis, rhabdomyolysis, or bile cast nephropathy. Acute kidney failure is not uncommon in severe WD patients, and independently increases mortality. Finally, specific and long-term therapy by D-penicillamin, one of the most efficient drugs in WD, can cause glomerular injuries, such as membranous nephropathy, minimal-change disease, and, rarely, severe glomerulonephritis. Altogether, our study supports the need for interdisciplinary evaluation of WD patients involving nephrologists, with regular monitoring of tubular and glomerular functions, to provide adequate prevention of renal and bone involvement.

UNASSIGNED: Systemic lupus erythematosus is an autoimmune disease with diverse clinical manifestations. The symptoms of SLE in children are more atypical than adults. Childhood SLE complicated with Fanconi syndrome is extremely rare and even more difficult to diagnose.
UNASSIGNED: This article reports a preschool boy with SLE who presented with renal tubular acidosis, accompanied by weakness in both lower limbs, delayed growth, and malnutrition. It was later found that the patient had the complication of Fanconi syndrome with renal tubular acidosis. Ultimately, renal biopsy confirmed lupus nephritis. The patient was treated with corticosteroid combined with mycophenolate mofetil, hydroxychloroquine, and belimumab. The symptoms of the child were relieved.
UNASSIGNED: Here we report an extremely rare case of childhood SLE complicated with Fanconi syndrome. There has been no similar clinical report. It is necessary to be alert to the possibility of atypical SLE in children to avoid missed diagnosis and misdiagnosis.

Cystinosis is a rare autosomal recessive lysosomal storage disorder characterized by cystine buildup in various tissues, including the kidneys. Renal involvement is the primary manifestation, leading to end-stage renal disease (ESRD) if left untreated. Kidney transplantation (KT) in patients with cystinosis has significantly improved their prognosis for the disease outcome. Detailed reports on preoperative and Long-term postoperative management in these patients remain sparse. This report discusses the outcomes of two young adult patients of Middle Eastern descent with cystinosis who underwent KT. The first patient, diagnosed with infantile nephropathic cystinosis treated by cystine-depleting therapy, was operated by KT at the age of 18. The second patient, diagnosed with juvenile cystinosis, underwent transplantation at the age of 35 after being treated with hemodialysis. Our report describes detailed pre- and postoperative managements, including laboratory results, and pharmacological interventions. Both cases highlighted the varying clinical manifestations and disease severity between infantile and juvenile cystinosis. Pre-transplant conditions included renal dysfunction, growth retardation, secondary hyperparathyroidism, anemia, and extrarenal manifestations. Following KT, both patients experienced regained renal function, resolution of extrarenal complications, and normalization of laboratory parameters. Furthermore, both patients showed excellent postoperative outcomes with no acute rejection or allograft-related complications. KT is the treatment of choice for cystinosis patients with ESRD. Long-term follow-up post-transplantation is crucial to maintain good graft function. Further studies may elucidate optimal pre- and postoperative management protocols for this rare condition.

Tenofovir disoproxil fumarate (TDF) is a nucleotide reverse transcriptase inhibitor that has been widely used for the treatment of patients with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) infections. Despite the excellent safety records of this regimen, a few cases of acute renal failure and Fanconi syndrome have been reported among HIV patients exposed to TDF. However, in the HBV monoinfection scenario, only five cases of TDF-associated Fanconi syndrome have been reported thus far, two of them providing a confirmatory kidney biopsy. Here, we describe the case of a 68-year-old woman with chronic hepatitis B (CHB) who developed TDF-induced Fanconi syndrome that reverted after TDF withdrawal from tenofovir alafenamide. Though the overall risk of TDF-associated severe renal toxicity in HBV patients appears to be negligible, both glomerular and tubular functions should be monitored in patients exposed to TDF.

UNASSIGNED: Fanconi\'s syndrome (FS) is characterized by type-2 renal tubular acidosis, short stature, and renal rickets, along with glycosuria, aminoaciduria, hypophosphaturia, and urinary bicarbonate wasting. The genetic form of FS has been linked to HNF4A variants. Although additional clinical features such as hearing impairment have recently been associated with HNF4A-linked FS, its ocular manifestation has not been described.
UNASSIGNED: Presenting a case of a 5-year-old male child with bilateral progressive corneal opacification and the presence of bilateral greyish-white deposits in the interpalpebral region since infancy. A next-generation sequencing (NGS)-based genetic testing was performed for the child followed by parental genetic testing for the identified variant. Furthermore, relevant works of literature were reviewed related to this condition.
UNASSIGNED: Detailed corneal findings showed a bilateral band-shaped keratopathy (BSK) in the patient. Physical and systemic findings showed signs consistent with FS. Sequencing analysis revealed a novel heterozygous c.635C>T, (p.Pro212Leu) variant in the HNF4A gene in the proband and mother, while the father had a normal genotype.
UNASSIGNED: Our case highlights the occurrence of BSK in an exceptionally rare manifestation of hereditary FS linked to HNF4A gene variant. The variant exists both in proband and asymptomatic mother. Therefore, the variable penetrance which is known to exist in HNF4A is acknowledged in this context. This report suggests the first documented instance establishing a plausible connection between BSK and HNF4A-associated FS, characterized by the variable penetrance attributed to the HNF4A gene.

UNASSIGNED: Several cases of Fanconi syndrome (FS), a severe form of nephrotoxicity, have been reported in patients with HIV on tenofovir-containing antiretroviral therapy. A systematic review of the published literature on tenofovir-related FS in patients with HIV was conducted.
UNASSIGNED: PubMed and Embase were queried to identify articles in English published between January 2005 and June 2023, reporting tenofovir-related FS in adults with HIV. Preclinical studies, conference/poster abstracts, commentaries and responses, and review papers were excluded.
UNASSIGNED: Of the 256 articles screened, 57 met the inclusion criteria. These comprised 37 case reports, 11 case series, 1 cross-sectional study, 1 case-control study, 4 cohort studies, 1 single-arm open-label clinical trial, 1 sub-analysis of clinical trials, and 1 pooled analysis of clinical trials.
UNASSIGNED: Among 56 cases on which information was abstracted, median age at FS diagnosis was 50 years, 51.8% were men, and duration of tenofovir use ranged from 6 weeks to 11 years. Ritonavir was co-prescribed in almost half the cases. In observational and interventional studies, incidence of FS was low. Many studies reported resolution of FS symptoms after tenofovir discontinuation. All FS occurrences were identified in those on tenofovir disoproxil fumarate (TDF), except for one patient on tenofovir alafenamide (TAF).
UNASSIGNED: Continuous monitoring of signs and symptoms of renal and bone toxicity is essential for patients with HIV on tenofovir-containing therapy.
UNASSIGNED: Occurrence of FS is low in patients with HIV treated with tenofovir-based regimens. Concomitant use of ritonavir may increase risk of FS. TAF may be a safer alternative than TDF in terms of nephrotoxicity.

We present the case of a woman of 50 years of age who experienced widespread bone pain along with digestive symptoms, including nausea and vomiting. She had been prescribed tenofovir disoproxil fumarate (TDF) tablets for the treatment of hepatitis B. Laboratory testing revealed low circulating phosphorus and potassium concentrations and acidosis. A whole-body bone scan revealed abnormal bone metabolism. Rheumatologic and urologic conditions were ruled out, and therefore TDF-induced Fanconi syndrome (FS) and related bone pain was diagnosed. After the TDF was discontinued, the patient\'s symptoms and laboratory indices significantly improved. In this manuscript, we highlight the clinical manifestations of and laboratory test results associated with FS and summarize the cases of TDF-induced FS reported on PubMed between 2013 and 2022 to improve understanding of FS.