Clinical Practice Recommendations on Kidney Management in Methylmalonic Acidemia: an Expert Consensus Statement From ERKNet and MetabERN.

Methylmalonic acidemias (MMAs) are rare inherited metabolic diseases with multiorgan involvement. Chronic kidney disease (CKD) is a common complication, leading to kidney failure, dialysis, and kidney transplantation (KT). The objective of these guidelines was to develop clinical practice recommendations focusing on specific aspects of the kidney management of this disease.

Bardet-Biedl syndrome improved diagnosis criteria and management: Inter European Reference Networks consensus statement and recommendations.

Four European Reference Networks (ERN-EYE, ERKNet, Endo-ERN, ERN-ITHACA) have teamed up to establish a consensus statement and recommendations for Bardet-Biedl syndrome (BBS). BBS is an autosomal recessive ciliopathy with at least 26 genes identified to date. The clinical manifestations are pleiotropic, can be observed in utero and will progress with age.

The SGLT2 inhibitor dapagliflozin improves kidney function in glycogen storage disease XI.

Glycogen storage disease XI, also known as Fanconi-Bickel syndrome (FBS), is a rare autosomal recessive disorder caused by mutations in the gene that encodes the glucose-facilitated transporter type 2 (GLUT2). Patients develop a life-threatening renal proximal tubule dysfunction for which no treatment is available apart from electrolyte replacement. To investigate the renal pathogenesis of FBS, expression was ablated in mouse kidney and HK-2 proximal tubule cells.

Cyclosporin-induced hypertension is associated with the up-regulation of Na+-K+-2Cl- cotransporter (NKCC2).

Background: The use of cyclosporin A (CsA) is hampered by the development of nephrotoxicity including hypertension, which is partially dependent on renal sodium retention. To address this issue, we have investigated in vivo sodium reabsorption in different nephron segments of CsA-treated rats through micropuncture study coupled to expression analyses of sodium transporters. To translate the findings in rats to human, kidney-transplanted patients having CsA treatment were enrolled in the study.

Next-Generation Sequencing (NGS) Analysis Illustrates the Phenotypic Variability of Collagen Type IV Nephropathies.

Mutations in cause a spectrum of glomerular disorders, including thin basement membrane nephropathy (TBMN) and Alport syndrome (AS). The wide application of next-generation sequencing (NGS) in the last few years has revealed that mutations in these genes are not limited to these clinical entities. In this study, 176 individuals with a clinical diagnosis of inherited kidney disorders underwent an NGS-based analysis to address the underlying cause; those who changed or perfected the clinical diagnosis after molecular analysis were selected.

Bardet-Biedl Syndrome: Current Perspectives and Clinical Outlook.

The Bardet Biedl syndrome (BBS) is a rare inherited disorder considered a model of non-motile ciliopathy. It is in fact caused by mutations of genes encoding for proteins mainly localized to the base of the cilium. Clinical features of BBS patients are widely shared with patients suffering from other ciliopathies, especially autosomal recessive syndromic disorders; moreover, mutations in cilia-related genes can cause different clinical ciliopathy entities.

Computational and Structural Analysis to Assess the Pathogenicity of Bardet-Biedl Syndrome Related Missense Variants Identified in Bardet-Biedl Syndrome 10 Gene (BBS10).

Bardet-Biedl Syndrome (BBS) is a rare inherited disorder resulting in multiple organ dysfunctions, whose cardinal clinical features include cognitive impairment, obesity, and renal dysfunction. Although it is highly heterogeneous at genetic levels, is one of the major causative genes worldwide. The BBS10 protein is part of a multiprotein complex localized at the basal body of the primary cilium.

Metabolomic fingerprinting of renal disease progression in Bardet-Biedl syndrome reveals mitochondrial dysfunction in kidney tubular cells.

Chronic kidney disease (CKD) is a major clinical sign of patients with Bardet-Biedl syndrome (BBS), especially in those carrying mutations. Twenty-nine patients with BBS and 30 controls underwent a serum-targeted metabolomic analysis. studies were conducted in two kidney-derived epithelial cell lines, where was stably deleted (IMCD3--/-cells) and over-expressed.

Multi-Omics Studies Unveil Extraciliary Functions of BBS10 and Show Metabolic Aberrations Underlying Renal Disease in Bardet-Biedl Syndrome.

Bardet-Biedl syndrome (BBS) is a rare autosomal recessive ciliopathy resulting in multiple organ dysfunctions, including chronic kidney disease (CKD). Despite the recent progress in the 'ciliopathy' field, there is still little information on the mechanisms underlying renal disease. To elucidate these pathomechanisms, we conducted a translational study, including (i) the characterization of the urine metabolomic pattern of BBS patients and controls in a pilot and confirmation study and (ii) the proteomic analysis of the BBS10 interactome, one of the major mutated BBS genes in patients, in a renal-epithelial-derived cell culture model.

miRNA-23a modulates sodium-hydrogen exchanger 1 expression: studies in medullary thick ascending limb of salt-induced hypertensive rats.

Background: The kidney is the main organ in the pathophysiology of essential hypertension. Although most bicarbonate reabsorption occurs in the proximal tubule, the medullary thick ascending limb (mTAL) of the nephron also maintains acid-base balance by contributing to 25% of bicarbonate reabsorption. A crucial element in this regulation is the sodium-hydrogen exchanger 1 (NHE1), a ubiquitous membrane protein controlling intracellular pH, where proton extrusion is driven by the inward sodium flux.

Bardet-Biedl syndrome: The pleiotropic role of the chaperonin-like BBS6, 10, and 12 proteins.

Bardet-Biedl syndrome (BBS) is a rare pleiotropic disorder known as a ciliopathy. Despite significant genetic heterogeneity, BBS1 and BBS10 are responsible for major diagnosis in western countries. It is well established that eight BBS proteins, namely BBS1, 2, 4, 5, 7, 8, 9, and 18, form the BBSome, a multiprotein complex serving as a regulator of ciliary membrane protein composition.

Guidelines for Genetic Testing and Management of Alport Syndrome.

Genetic testing for pathogenic variants is usually undertaken to investigate the cause of persistent hematuria, especially with a family history of hematuria or kidney function impairment. Alport syndrome experts now advocate genetic testing for persistent hematuria, even when a heterozygous pathogenic or is suspected, and cascade testing of their first-degree family members because of their risk of impaired kidney function. The experts recommend too that or heterozygotes do not act as kidney donors.

Brain dysfunction in tubular and tubulointerstitial kidney diseases.

Kidney function has two important elements: glomerular filtration and tubular function (secretion and reabsorption). A persistent decrease in glomerular filtration rate (GFR), with or without proteinuria, is diagnostic of chronic kidney disease (CKD). While glomerular injury or disease is a major cause of CKD and usually associated with proteinuria, predominant tubular injury, with or without tubulointerstitial disease, is typically non-proteinuric.

Diffusion tensor imaging for the study of early renal dysfunction in patients affected by bardet-biedl syndrome.

Kidney structural abnormalities are common features of Bardet-Biedl syndrome (BBS) patients that lead to a progressive decline in renal function. Magnetic resonance diffusion tensor imaging (DTI) provides useful information on renal microstructures but it has not been applied to these patients. This study investigated using DTI to detect renal abnormalities in BBS patients with no overt renal dysfunction.

Urine concentrating defect as presenting sign of progressive renal failure in Bardet-Biedl syndrome patients.

Background: Urine concentrating defect is a common dysfunction in ciliopathies, even though its underlying mechanism and its prognostic meaning are largely unknown. This study assesses renal function in a cohort of 54 Bardet-Biedl syndrome (BBS) individuals and analyses whether renal hyposthenuria is the result of specific tubule dysfunction and predicts renal disease progression.

Methods: The estimated glomerular filtration rate (eGFR), urine albumin:creatinine ratio (ACR) and maximum urine osmolality (max-Uosm) were measured in all patients.

A case series of adult patients affected by EAST/SeSAME syndrome suggests more severe disease in subjects bearing truncating mutations.

EAST/SeSAME syndrome is a rare disease affecting the Central Nervous System (CNS), inner ear, and kidney. The syndrome is due to loss-of-function mutations in the gene encoding the inward-rectifying potassium channel Kir4.1.

Nephroplex: a kidney-focused NGS panel highlights the challenges of PKD1 sequencing and identifies a founder BBS4 mutation.

Background: Genetic testing of patients with inherited kidney diseases has emerged as a tool of clinical utility by improving the patients' diagnosis, prognosis, surveillance and therapy.

Methods: The present study applied a Next Generation Sequencing (NGS)-based panel, named NephroPlex, testing 115 genes causing renal diseases, to 119 individuals, including 107 probands and 12 relatives. Thirty-five (poly)cystic and 72 non (poly)cystic individuals were enrolled.

Urinary proteomics reveals key markers of salt sensitivity in hypertensive patients during saline infusion.

Background: Hypertension is a complex disease and is the major cause of cardiovascular complications. In the vast majority of individuals, the aetiology of elevated blood pressure (BP) cannot be determined, thus impairing optimized therapies and prognosis for individual patients. A more precise understanding of the molecular pathogenesis of hypertension remains a pressing priority for both basic and translational research.

Treatment and long-term outcome in primary nephrogenic diabetes insipidus.

Background: Primary nephrogenic diabetes insipidus (NDI) is a rare disorder and little is known about treatment practices and long-term outcome.

Methods: Paediatric and adult nephrologists contacted through European professional organizations entered data in an online form.

Results: Data were collected on 315 patients (22 countries, male 84%, adults 35%).

Exploring Key Challenges of Understanding the Pathogenesis of Kidney Disease in Bardet-Biedl Syndrome.

Bardet-Biedl syndrome (BBS) is a rare pleiotropic inherited disorder known as a ciliopathy. Kidney disease is a cardinal clinical feature; however, it is one of the less investigated traits. This study is a comprehensive analysis of the literature aiming to collect available information providing mechanistic insights into the pathogenesis of kidney disease by analyzing clinical and basic science studies focused on this issue.