Postnatal outcome of children with antenatal colonic hyperechogenicity.

Objective: To evaluate the postnatal outcome of children with antenatal colonic hyperechogenicity, currently considered as a sign of lysinuria-cystinuria, but which may also be a sign of other disorders with a more severe prognosis.

Method: We carried out a French multi-centric retrospective study via 15 Multidisciplinary Center for Prenatal Diagnosis from January 2011 to January 2021. We included pregnancies for which fetal colonic hyperechogenicity had been demonstrated.

Further delineation of the rare GDACCF (global developmental delay, absent or hypoplastic corpus callosum, dysmorphic facies syndrome): genotype and phenotype of 22 patients with mutations.

Background: Pathogenic variants in the zinc finger protein coding genes are rare causes of intellectual disability and congenital malformations. Mutations in the gene causing GDACCF syndrome (global developmental delay, absent or hypoplastic corpus callosum, dysmorphic facies; MIM #617260) have been reported in five individuals so far.

Methods: As a result of an international collaboration using GeneMatcher Phenome Central Repository and personal communications, here we describe the clinical and molecular genetic characteristics of 22 previously unreported individuals.

[Epidemiology of childhood chronic kidney diseases].

Major advances have been made in the management of children with chronic kidney disease (CKD) over the past 30 years. However, existing epidemiological data mainly relies on registries of chronic kidney replacement therapy. The incidence and prevalence of earlier stages of CKD remain largely unknown, but rare population-based studies suggest that the prevalence of all stages CKD may be as high as 1 % of the pediatric population.

Renal Prognosis in Children With Tubulointerstitial Nephritis and Uveitis Syndrome.

Introduction: Tubulointerstitial nephritis (TIN) and uveitis (TINU) syndrome is a rare disease. The renal prognosis is generally thought to be better in children with TINU syndrome than in adults. However, data are scarce.

Efficacy and safety of intravenous immunoglobulin with rituximab versus rituximab alone in childhood-onset steroid-dependent and frequently relapsing nephrotic syndrome: protocol for a multicentre randomised controlled trial.

Introduction: Guidelines for the treatment of steroid-dependent nephrotic syndrome (SDNS) and frequently relapsing nephrotic syndrome (FRNS) are lacking. Given the substantial impact of SDNS/FRNS on quality of life, strategies aiming to provide long-term remission while minimising treatment side effects are needed. Several studies confirm that rituximab is effective in preventing early relapses in SDNS/FRNS; however, the long-term relapse rate remains high (~70% at 2 years).

Adherence to cysteamine in nephropathic cystinosis: A unique electronic monitoring experience for a better understanding. A prospective cohort study: CrYSTobs.

Introduction: In nephropathic cystinosis (NC), adherence to cysteamine remains challenging; poor adherence is worsening the disease progression with a decline of kidney function and increase of extrarenal morbidities. Our objective was to describe adherence to cysteamine in NC patients, using electronic monitoring systems.

Methods: Patients with confirmed NC, aged > 4 years and receiving oral cysteamine (short acting or delayed release formulation as standard of care) from 3 French reference centers, were included.

Mycophenolic acid area under the concentration-time curve is associated with therapeutic response in childhood-onset lupus nephritis.

Background: Mycophenolic acid (MPA), the active compound of mycophenolate mofetil (MMF), is widely used in lupus nephritis treatment. Therapeutic drug monitoring of adults suggests that area under the concentration-time curve (AUC) of MPA (MPA-AUC) is associated with clinical outcomes, but childhood data are scarce.

Methods: Retrospective study of 27 children with biopsy-proven lupus nephritis treated with MMF between 2008 and 2016.

[Not Available].

Rare diseases usually concern small and disseminated population. Implementing clinical research with the right design, outcomes measures and the recruitment of patients are challenges. Collaborations, training and multidisciplinary approach are often required.

Neuropsychological and neuroanatomical phenotype in 17 patients with cystinosis.

Background: Cystinosis is a rare autosomal recessive disorder caused by intracellular cystine accumulation. Proximal tubulopathy (Fanconi syndrome) is one of the first signs, leading to end-stage renal disease between the age of 12 and 16. Other symptoms occur later and encompass endocrinopathies, distal myopathy and deterioration of the central nervous system.

Adverse events associated with currently used medical treatments for cystinuria and treatment goals: results from a series of 442 patients in France.

Objective: To evaluate medical treatments, in terms of adverse events (AEs) and therapeutic goals, in a large series of patients with cystinuria.

Patients And Methods: Data from 442 patients with cystinuria were recorded retrospectively. Crystalluria was studied in 89 patients.

[Proteinuria in pediatrics: from screening to diagnosis and monitoring of kidney disease].

The incidental finding of a proteinuria is a common cause of consultation in pediatric nephrology. Although it is transient in most cases, it may also be indicative of a kidney disease. For this reason, a moderate proteinuria in children should not be overlooked.

Patient and transplant outcome in infants starting renal replacement therapy before 2 years of age.

Background: Despite major technical improvements in the care of children requiring renal replacement therapy (RRT) before 2 years of age, the management of those patients remains challenging and transplantation is generally delayed until the child weighs 10 kg or is 2 years old. In this national cohort study, we studied patient and graft survival in children starting RRT before 2 years of age to help clinicians and parents when deciding on RRT initiation and transplantation management.

Methods: All children starting RRT before 24 months of age between 1992 and 2012 in France were included through the national Renal Epidemiology and Information Network (REIN) registry.

Prevalence of Novel Mutations in Antenatal Bartter Syndrome.

Background And Objectives: Mutations in the gene, located on the X chromosome, have been recently detected in males with a transient form of antenatal Bartter syndrome or with idiopathic polyhydramnios. The aim of this study is to analyze the proportion of the population with mutations in this gene in a French cohort of patients with antenatal Bartter syndrome.

Design, Setting, Participants, & Measurements: The French cohort of patients with antenatal Bartter syndrome encompasses 171 families.

Mycophenolic Acid Pharmacokinetics and Relapse in Children with Steroid-Dependent Idiopathic Nephrotic Syndrome.

Background And Objectives: Therapeutic drug monitoring of mycophenolic acid can improve clinical outcome in organ transplantation and lupus, but data are scarce in idiopathic nephrotic syndrome. The aim of our study was to investigate whether mycophenolic acid pharmacokinetics are associated with disease control in children receiving mycophenolate mofetil for the treatment of steroid-dependent nephrotic syndrome.

Design, Setting, Participants, & Measurements: This was a retrospective multicenter study including 95 children with steroid-dependent nephrotic syndrome treated with mycophenolate mofetil with or without steroids.

Mutation Update of the CLCN5 Gene Responsible for Dent Disease 1.

Dent disease is a rare X-linked tubulopathy characterized by low molecular weight proteinuria, hypercalciuria, nephrocalcinosis and/or nephrolithiasis, progressive renal failure, and variable manifestations of other proximal tubule dysfunctions. It often progresses over a few decades to chronic renal insufficiency, and therefore molecular characterization is important to allow appropriate genetic counseling. Two genetic subtypes have been described to date: Dent disease 1 is caused by mutations of the CLCN5 gene, coding for the chloride/proton exchanger ClC-5; and Dent disease 2 by mutations of the OCRL gene, coding for the inositol polyphosphate 5-phosphatase OCRL-1.

CKD and Its Risk Factors among Patients with Cystinuria.

Background And Objectives: Cystinuria is an autosomal recessive disorder affecting renal cystine reabsorption; it causes 1% and 8% of stones in adults and children, respectively. This study aimed to determine epidemiologic and clinical characteristics as well as comorbidities among cystinuric patients, focusing on CKD and high BP.

Design, Setting, Participants, & Measurements: This retrospective study was conducted in France, and involved 47 adult and pediatric nephrology and urology centers from April 2010 to January 2012.

[Vasopressin V2 receptor-related pathologies: congenital nephrogenic diabetes insipidus and nephrogenic syndrome of inappropiate antidiuresis].

Congenital nephrogenic diabetes insipidus is a rare hereditary disease with mainly an X-linked inheritance (90% of the cases) but there are also autosomal recessive and dominant forms. Congenital nephrogenic diabetes insipidus is characterized by a resistance of the renal collecting duct to the action of the arginine vasopressin hormone responsible for the inability of the kidney to concentrate urine. The X-linked form is due to inactivating mutations of the vasopressin 2 receptor gene leading to a loss of function of the mutated receptors.

Towards a new point of view on the phenotype of patients with a 17q12 microdeletion syndrome.

Objective: 17q12 microdeletion syndrome involves 15 genes, including HNF1B, and is considered to confer a high risk of neuropsychiatric disorders. Patients with HNF1B gene deletion diagnosed secondary to renal disorders are only very rarely reported to have neuropsychiatric disorders. Interestingly, however, when tested, patients with HNF1B gene deletion are found to have 17q12 deletion.

Quality of life is improved and kidney function preserved in patients with nephropathic cystinosis treated for 2 years with delayed-release cysteamine bitartrate.

Objectives: To determine the long-term effects of delayed-release cysteamine bitartrate (DR-CYS) based on our previous work that established the short-term noninferiority of DR-CYS every 12 hours compared with immediate-release cysteamine bitartrate every 6 hours.

Study Design: We conducted a prospective, controlled, open label, single-arm study of DR-CYS for 2 years in 40 patients to assess efficacy in depletion of cystine in peripheral white blood cells, to assess the dose required to maintain white blood cell content of cystine <1 nmol ½ cystine/mg protein, to measure quality of life using the Pediatric Quality of Life Inventory, change in estimated glomerular filtration rate, and change in height Z-score.

Results: Through 24 months of study, the mean white blood cell content of cystine was always <1 nmol ½ cystine/mg protein, and the dose of DR-CYS decreased from 43.

C3 nephritic factor associated with C3 glomerulopathy in children.

Background: C3 glomerulopathy (C3G) is characterized by predominant C3 deposits in glomeruli and dysregulation of the alternative pathway of complement. Half of C3G patients have a C3 nephritic factor (C3NeF). C3G incorporated entities with a range of features on microscopy including dense deposit diseases (DDD) and C3 glomerulonephritis (C3GN).

Recessive mutations in DGKE cause atypical hemolytic-uremic syndrome.

Pathologic thrombosis is a major cause of mortality. Hemolytic-uremic syndrome (HUS) features episodes of small-vessel thrombosis resulting in microangiopathic hemolytic anemia, thrombocytopenia and renal failure. Atypical HUS (aHUS) can result from genetic or autoimmune factors that lead to pathologic complement cascade activation.