Clinical practice recommendations for the diagnosis and management of X-linked hypophosphataemia.

X-linked hypophosphataemia (XLH) is a rare metabolic bone disorder caused by pathogenic variants in the PHEX gene, which is predominantly expressed in osteoblasts, osteocytes and odontoblasts. XLH is characterized by increased synthesis of the bone-derived phosphaturic hormone fibroblast growth factor 23 (FGF23), which results in renal phosphate wasting with consecutive hypophosphataemia, rickets, osteomalacia, disproportionate short stature, oral manifestations, pseudofractures, craniosynostosis, enthesopathies and osteoarthritis. Patients with XLH should be provided with multidisciplinary care organized by a metabolic bone expert.

Achievements, priorities and strategies in pediatric nephrology in Europe: need for unifying approaches or acceptance of differences?

Background: There is a lack of information on the current healthcare systems for children with kidney diseases across Europe. The aim of this study was to explore the different national approaches to the organization and delivery of pediatric nephrology services within Europe.

Methods: In 2020, the European society for Paediatric Nephrology (ESPN) conducted a cross-sectional survey to identify the existing pediatric nephrology healthcare systems in 48 European countries covering a population of more than 200 million children.

C3 glomerulopathy in children: a European longitudinal study evaluating outcome.

Background: C3 glomerulopathy is a rare clinical entity characterized by dysregulation of the alternative complement pathway in glomerular disease. Studies defining the natural history of C3G in the pediatric population are scarce.

Methods: Patients included in this retrospective study were diagnosed between 2011 and 2020 in 12 European pediatric nephrology units.

Dried Blood Spot Sampling for Monitoring Children With Immune-Mediated Glomerulopathies and After Kidney Transplantation.

Introduction: Monitoring kidney function and immunosuppressant levels in children post-kidney transplantation or those with glomerulopathies is challenging due to frequent venipunctures and clinic visits. Capillary dried blood spot sampling (DBS) offers a potential alternative.

Methods: In this prospective single-center study, 89 children (38% female and 62% male) requiring therapeutic drug monitoring (TDM) and kidney function assessment were enrolled.

BCL11A intellectual developmental disorder: defining the clinical spectrum and genotype-phenotype correlations.

An increasing number of individuals with intellectual developmental disorder (IDD) and heterozygous variants in BCL11A are identified, yet our knowledge of manifestations and mutational spectrum is lacking. To address this, we performed detailed analysis of 42 individuals with BCL11A-related IDD (BCL11A-IDD, a.k.

Different growth patterns in two siblings with Schimke immuno-osseous-dysplasia.

Schimke immuno-osseous-dysplasia (SIOD) is an autosomal recessive systemic disease due to pathogenic variants in SMARCAL1. Manifestations include nephrotic syndrome (NS), kidney failure, T-cell dysfunction, vaso-occlusive disease, and disproportionate short stature, a general feature of this disease. Here, we present a markedly different growth pattern in two brothers with SIOD sharing the same homozygous R561C missense variant.

Safety and Efficacy of Cinacalcet in Children Aged Under 3 Years on Maintenance Dialysis.

Introduction: Secondary hyperparathyroidism (sHPT) is particularly severe in rapidly growing infants in dialysis. Although cinacalcet is effective and licensed in dialysis in children aged >3 years, its efficacy and safety for children aged <3 years is unknown.

Methods: We identified 26 children aged <3 years who were on dialysis and treated with cinacalcet between 2009 and 2021 in 8 European pediatric centers.

Cystinosis-associated metabolic bone disease across ages and CKD stages 1-5D/T.

Context: The pathophysiology of cystinosis-associated metabolic bone disease is complex.

Objective: We hypothesized a disturbed interaction between osteoblasts and osteoclasts.

Design: Binational cross-sectional multicenter study.

Health-related quality of life of children with X-linked hypophosphatemia in Germany.

Background: X-linked hypophosphatemia (XLH) is a rare inherited phosphate-wasting disorder associated with bone and dental complications. Health-related quality of life (HRQoL) is reduced in XLH patients on conventional treatment with phosphate supplements and active vitamin D, while information on patients treated with burosumab is rare.

Methods: HRQoL was assessed in 63 pediatric XLH patients participating in a prospective, observational study and patient registry in Germany using the KIDSCREEN-52 survey instrument and standardized qualitative interviews.

Morphological changes and their associations with clinical parameters in children with nephropathic cystinosis and chronic kidney disease prior to kidney replacement therapy over 25 years.

Background: Infantile nephropathic cystinosis (INC) is a rare lysosomal storage disorder, mostly and often firstly affecting the kidneys, together with impaired disharmonious growth and rickets, eventually resulting in progressive chronic kidney disease (CKD). With the introduction of cysteamine therapy, most pediatric patients reach adulthood with no need for kidney replacement therapy. Still, detailed changes in INC patients' clinical and morphological presentation over the past decades have not yet been thoroughly investigated.

Assessment and management of vitamin status in children with CKD stages 2-5, on dialysis and post-transplantation: clinical practice points from the Pediatric Renal Nutrition Taskforce.

Children with chronic kidney disease (CKD) are at risk for vitamin deficiency or excess. Vitamin status can be affected by diet, supplements, kidney function, medications, and dialysis. Little is known about vitamin requirements in CKD, leading to practice variation.

Defects of renal tubular homeostasis and cystogenesis in the knockout.

Loss of -gene function causes autosomal recessive polycystic kidney disease (ARPKD) characterized by bilateral severely enlarged kidneys and congenital liver fibrosis requiring kidney replacement therapy most frequently during childhood. Studies using renal tissue from ARPKD patients suggest cyst promotion by suppressed hippo activity and enhanced Src/STAT3-signaling. We address renal homeostasis in female -knockout mice, aged 3 to 9 months, and observe features in common with late-onset ARPKD.

Diversity of kidney care referral pathways in national child health systems of 48 European countries.

Background: Primary, secondary and tertiary healthcare services in Europe create complex networks covering pediatric subspecialties, sociology, economics and politics. Two surveys of the European Society for Paediatric Nephrology (ESPN) in 1998 and 2017 revealed substantial disparities of kidney care among European countries. The purpose of the third ESPN survey is to further identify national differences in the conceptualization and organization of European pediatric kidney health care pathways during and outside normal working hours.

LMS-based continuous pediatric reference values for soluble receptor activator of nuclear factor kappa B ligand (sRANKL) and osteoprotegerin (OPG) in the HARP cohort.

Unlabelled: Soluble RANKL (sRANKL) and osteoprotegerin (OPG) are regulators of osteoclast differentiation and activation, but adequate pediatric reference values are lacking. Here we provide LMS (Lambda-Mu-Sigma)-based continuous pediatric reference percentiles for sRANKL, OPG and sRANKL/OPG ratio that will allow calculation of standardized patient z-scores to assess bone modeling in children.

Purpose: Soluble receptor activator of nuclear factor kappa B ligand (sRANKL) and osteoprotegerin (OPG) are regulators of osteoclast differentiation and activation and thus bone metabolic turnover in children.

LMS-Based Pediatric Reference Values for Parameters of Phosphate Homeostasis in the HARP Cohort.

Context: The assessment of phosphate homeostasis in children is challenging due to the marked changes in laboratory parameters during growth and development, and the lack of adequate reference values.

Objective: To develop Lambda-Mu-Sigma (LMS)-based continuous pediatric reference percentiles for 7 key laboratory parameters of phosphate homeostasis.

Methods: This cross-sectional, single-center study, the HAnnover Reference values for Pediatrics (HARP) study, included 455 children aged 0.