Growth references are useful in monitoring a child's growth, which is an essential part of child care. The aim of this paper was to provide updated growth references for Polish school-aged children and adolescents and show the prevalence of overweight and obesity among them. Growth references for height, weight, and body mass index (BMI) were constructed with the lambda, mu, sigma (LMS) method using data from a recent, large, population-representative sample of school-aged children and adolescents in Poland (n = 17,573). The prevalence of overweight and obesity according to the International Obesity Taskforce definition was determined with the use of LMSGrowth software. Updated growth references for Polish school-aged children and adolescents were compared with Polish growth references from the 1980s, the Warsaw 1996–1999 reference, German, and 2000 CDC references. A positive secular trend in height was observed in children and adolescents from 7 to 15 years of age. A significant shift of the upper tail of the BMI distribution occurred, especially in Polish boys at younger ages. The prevalence of overweight or obesity was 18.7% and 14.1% in school-aged boys and girls, respectively. The presented height, weight, and BMI references are based on a current, nationally representative sample of Polish children and adolescents without known disorders affecting growth. Changes in the body size of children and adolescents over the last three decades suggest an influence of the changing economical situation on anthropometric indices.

WT1 mutations cause a wide spectrum of renal and extrarenal manifestations. Here we evaluated disease prevalence, phenotype spectrum, and genotype-phenotype correlations of 61 patients with WT1-related steroid-resistant nephrotic syndrome relative to 700 WT1-negative patients, all with steroid-resistant nephrotic syndrome. WT1 patients more frequently presented with chronic kidney disease and hypertension at diagnosis and exhibited more rapid disease progression. Focal segmental glomerulosclerosis was equally prevalent in both cohorts, but diffuse mesangial sclerosis was largely specific for WT1 disease and was present in 34% of cases. Sex reversal and/or urogenital abnormalities (52%), Wilms tumor (38%), and gonadoblastoma (5%) were almost exclusive to WT1 disease. Missense substitutions affecting DNA-binding residues were associated with diffuse mesangial sclerosis (74%), early steroid-resistant nephrotic syndrome onset, and rapid progression to ESRD. Truncating mutations conferred the highest Wilms tumor risk (78%) but typically late-onset steroid-resistant nephrotic syndrome. Intronic (KTS) mutations were most likely to present as isolated steroid-resistant nephrotic syndrome (37%) with a median onset at an age of 4.5 years, focal segmental glomerulosclerosis on biopsy, and slow progression (median ESRD age 13.6 years). Thus, there is a wide range of expressivity, solid genotype-phenotype associations, and a high risk and significance of extrarenal complications in WT1-associated nephropathy. We suggest that all children with steroid-resistant nephrotic syndrome undergo WT1 gene screening.

We report one of the largest cohorts of FHHNC cases caused by CLDN16 mutations. A missense variant of CLDN16, Leu151Phe, is the most common mutation responsible for FHHNC in Poland. Additionally, we found that normomagnesaemia does not exclude FHHNC and the calculation of fractional excretion of Mg can be diagnostic in the setting of normomagnesaemia. We also demonstrate the efficacy of a treatment with thiazides in terms of hypercalciuria in the majority of patients.

We have identified clinical features in 28 patients with suspected Lowe syndrome that had not been recognized in Lowe syndrome prior to our study. We also provide further evidence that OCRL mutations cause a phenotypic continuum with selective and/or time-dependent organ involvement. At least some of these mutants might exhibit a genotype-phenotype correlation.

P < 0.001 (Fisher exact probability test).c l i n i c a l i n v e s t i g a t i o n AM _ Zurowska et al.: Mild Alport syndrome due to founder COL4A5 p.G624D AM _ Zurowska et al.: Mild Alport syndrome due to founder COL4A5 p.G624D c l i n i c a l i n v e s t i g a t i o n Kidney International (2021) -, ---AM _ Zurowska et al.: Mild Alport syndrome due to founder COL4A5 p.G624Dc l i n i c a l i n v e s t i g a t i o n