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Introduction: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease, which is mainly caused by pathogenic variants in two particular genes: PKD1 and PKD2. ADPKD caused by variants in other genes (GANAB or IFT140) is very rare. Case Report: In a 6-year-old girl examined for abdominal pain, a cystic mass in the upper part of the right kidney was detected during an abdominal ultrasound. She was referred to pediatric oncology and urology for suspicion of a tumorous mass and the condition was assessed as a cystic nephroma. A heminephrectomy was then performed on the upper cystic part of the right kidney. The histological examination was inconclusive; therefore, genetic testing was recommended. Kidney and liver cysts were detected sonographically in the mother, but DNA analysis of the PKD1 and PKD2 genes did not reveal any pathogenic variant; the cause of the pathological formation in the kidneys remained unclear. Nine years later, next-generation sequencing of a panel of genes for kidney disease was performed and a heterozygous deletion was found on chromosome 16; this included exon 13 of the IFT140 gene. The same deletion was found in the patient's mother. Currently, the patient is 14 years old and has mild sonographic findings, normal glomerular filtration, mild proteinuria, and hypertension. Conclusion: Pathogenic variants of the IFT140 gene very rarely cause ADPKD; however, they should be considered in all children with autosomal dominant forms of PKD and asymmetric/atypical cystic kidney involvement or negative findings of PKD1 and PKD2.
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INTRODUCTION: Static renal scintigraphy is the gold standard for detection of inflammatory changes in the renal parenchyma in acute pyelonephritis. Our aim was to determine whether diffusion-weighted magnetic resonance imaging (DW-MRI) was comparable with static renal scintigraphy (DMSA-SRS) to demonstrate acute renal parenchymal lesions. OBJECTIVE: To compare 99mTc-dimercaptosuccinic acid static renal scintigraphy (DMSA-SRS) with diffusion-weighted magnetic resonance imaging (DW-MRI) for detecting acute inflammatory changes in the renal parenchyma in children with febrile urinary tract infection. METHODS: Thirty-one children (30 girls) aged 3-18 years with a first episode of febrile UTI without a previously detected congenital malformation of the urinary tract, were prospectively included. DMSA-SRS and DW-MRI were performed within 5 days of diagnosis to detect renal inflammatory lesions. The DW-MRI examination was performed without contrast agent and without general anesthesia. Late examinations were performed after 6 months using both methods to detect late lesions. RESULTS: DW-MRI confirmed acute inflammatory changes of the renal parenchyma in all 31 patients (100%), mostly unilateral. DMSA-SRS detected inflammatory lesions in 22 children (71%; p = 0.002). The lesions were multiple in 26/31 children (84%) on DW-MRI and in 9/22 (40%) on DMSA-SRS. At the control examination, scarring of the renal parenchyma was found equally by DW-MRI and DMSA-SRS in five patients (16%), three of whom were the same patients. The overall concordance of positive and negative late findings occurred in 87% of patients. There was correspondence in the anatomical location of acute and late lesions. DISCUSSION: The clinical significance of acute and late parenchymal findings on DWI-MR is yet to be determined. A limitation of our study is the age of the patients (older than 3 years) who are less sensitive to scar development; therefore, a smaller number of patients with scars could be analyzed during control examination. Further studies using the DW-MRI should confirm its reliability to detect acute and late lesions in younger children and infants and determine the clinical consequences. CONCLUSION: DW-MRI has higher sensitivity for detecting acute renal inflammatory lesions and multifocal lesions than DMSA-SRS. The incidence of scars was low and corresponded with the anatomical location of acute and late lesions.
