Late-Onset Bartter Syndrome Type II Due to a Novel Compound Heterozygous Mutation in KCNJ1 Gene: A Case Report and Literature Review.

Background: Bartter syndrome (BS) type II is a rare autosomal recessive renal tubular disorder caused by mutations in the KCNJ1 gene, which encodes the apical renal outer medullary potassium (ROMK) channel in the thick ascending limb (TAL) of Henle's loop. BS type II is typically considered as a disorder of infancy and seldom seen in adults. Case Presentation: A 34-year-old woman was admitted with generalized body numbness and hand convulsions, without growth retardation. Laboratory tests revealed hypokalemic metabolic alkalosis, hyperreninemic hyperaldosteronism, and nephrocalcinosis. She was misdiagnosed during the initial diagnosis process and was finally diagnosed with late-onset BS type II via genetic testing through next-generation sequencing combined with Sanger sequencing. A novel compound heterozygous p.Leu207Ile/p. Cys308Arg variant in exon 5 of the KCNJ1 gene from her parents was identified and speculated to be a potential pathogenic gene variation. Conclusion: We report a case of late-onset BS type II with a novel compound heterozygous mutation in KCNJ1. Both variants are novel and have never been reported. Our report will have a significant impact on the diagnosis of BS in other patients without typical clinical presentations and emphasizes the importance of genetic investigation.

Immunoglobulin a nephropathy as the first clinical presentation of Wilson disease: a case report and literature review.

BACKGROUND: Wilson disease (WD) is a rare genetic disorder of copper metabolism. Differences in copper tissue accumulation lead to various clinical manifestations, including some atypical presentations. The complex clinical features of WD make diagnosis challenging, delaying the best chance for treatment. CASE PRESENTATION: We report a case of a 26-year-old man with nephritis-range proteinuria and elevated serum creatinine. The renal pathology indicated immunoglobulin A (IgA) nephropathy and tubular injury, which was inconsistent with glomerular lesions. Cirrhosis was also detected by imaging examination. Considering both kidney injury and liver damage, WD was suspected. Based on results showing abnormal copper metabolism, corneal Kayser-Fleischer rings, and genetic disorders in the ATP7B gene, the patient was finally diagnosed with WD. After treatment with oral penicillamine, zinc sulfate and losartan, the patient showed alleviation of both WD and nephropathy after 3 years of follow-up. He maintained a good quality of daily life. CONCLUSION: This case highlights that unexplained neurological and liver symptoms in patients with IgA nephropathy can be clues for WD.

[Value of urinary kidney injury molecule-1 protein in early diagnosis of radiocontrast- induced nephropathy in rats].

OBJECTIVE: To assess the value of determination of urine kidney injury molecule-1 (KIM-1) protein content in the early diagnosis of radiocontrast-induced nephropathy (RCIN) in rats. METHODS: Seventy-two adult male SD rats were randomly divided into groups A, B, C (n=8) and D group (which was subdivided into 2, 6, 12, 24, 48 h and 7 days groups, n=8). Group A was subject to injections via the tail vein of PBS and normal saline (NS), group B received injections of PBS, NS, and contrast medium (CM), group C with indomethacin (INDO), nitric oxide synthase inhibitor (L-NAME), and NS, and group D with INDO, L-NAME and CM. Each injection was given at the interval of 15 min. RESULTS: In group D, serum creatinine (Scr) and urea nitrogen (BUN) were significantly increased at 6 h after the injections (P<0.001), peaked at 24 h and recovered normal levels at 48 h. Histological examination revealed significant pathological changes in the kidneys at 6 h, showing diffuse tubulointerstitial hyperemia and hemorrhage, marked tubular necrosis and tubular structure destruction; at 12 h, significant tubular necrosis was still present with tubular structure destruction, but the tubulointerstitial hemorrhage was alleviated; at 24 h, tubular regeneration occurred in the renal medulla, but even till 7 days the tubular structures failed to show full recovery. In group D, urine KIM-1 level began to increase at 2 h, reached the peak level at 24 h, and lasted till 7 days (P<0.001); urine N-acetly-ß-D-glucosaminidase (NAG) value began to increase at 6 h and became normal at 48 h. Urine MMP-9 level underwent no significant changes in group D over the time points of observation. CONCLUSION: The results show that urinary KIM-1 levels can be used as an indicator for early diagnosis of RCIN.