We examined the burden of large, rare, copy-number variants (CNVs) in 192 individuals with renal hypodysplasia (RHD) and replicated findings in 330 RHD cases from two independent cohorts. CNV distribution was significantly skewed toward larger gene-disrupting events in RHD cases compared to 4,733 ethnicity-matched controls (p = 4.8 × 10(-11)). This excess was attributable to known and novel (i.e., not present in any database or in the literature) genomic disorders. All together, 55/522 (10.5%) RHD cases harbored 34 distinct known genomic disorders, which were detected in only 0.2% of 13,839 population controls (p = 1.2 × 10(-58)). Another 32 (6.1%) RHD cases harbored large gene-disrupting CNVs that were absent from or extremely rare in the 13,839 population controls, identifying 38 potential novel or rare genomic disorders for this trait. Deletions at the HNF1B locus and the DiGeorge/velocardiofacial locus were most frequent. However, the majority of disorders were detected in a single individual. Genomic disorders were detected in 22.5% of individuals with multiple malformations and 14.5% of individuals with isolated urinary-tract defects; 14 individuals harbored two or more diagnostic or rare CNVs. Strikingly, the majority of the known CNV disorders detected in the RHD cohort have previous associations with developmental delay or neuropsychiatric diseases. Up to 16.6% of individuals with kidney malformations had a molecular diagnosis attributable to a copy-number disorder, suggesting kidney malformations as a sentinel manifestation of pathogenic genomic imbalances. A search for pathogenic CNVs should be considered in this population for the diagnosis of their specific genomic disorders and for the evaluation of the potential for developmental delay.

Congenital anomalies of the kidney and urinary tract (CAKUT) are a major cause of pediatric kidney failure. We performed a genome-wide analysis of copy number variants (CNVs) in 2,824 cases and 21,498 controls. Affected individuals carried a significant burden of rare exonic (i.e. affecting coding regions) CNVs and were enriched for known genomic disorders (GD). Kidney anomaly (KA) cases were most enriched for exonic CNVs, encompassing GD-CNVs and novel deletions; obstructive uropathy (OU) had a lower CNV burden and an intermediate prevalence of GD-CNVs; vesicoureteral reflux (VUR) had the fewest GD-CNVs but was enriched for novel exonic CNVs, particularly duplications. Six loci (1q21, 4p16.1-p16.3, 16p11.2, 16p13.11, 17q12, and 22q11.2) accounted for 65% of patients with GD-CNVs. Deletions at 17q12, 4p16.1-p16.3, and 22q11.2 were specific for KA; the 16p11.2 locus showed extensive pleiotropy. Using a multidisciplinary approach, we identified TBX6 as a driver for the CAKUT subphenotypes in the 16p11.2 microdeletion syndrome.

BACKGROUND The DiGeorge syndrome, the most common of the microdeletion syndromes, affects multiple organs, including the heart, the nervous system, and the kidney. It is caused by deletions on chromosome 22q11.2; the genetic driver of the kidney defects is unknown. METHODS We conducted a genomewide search for structural variants in two cohorts: 2080 patients with congenital kidney and urinary tract anomalies and 22,094 controls. We performed exome and targeted resequencing in samples obtained from 586 additional patients with congenital kidney anomalies. We also carried out functional studies using zebrafish and mice. RESULTS We identified heterozygous deletions of 22q11.2 in 1.1% of the patients with congenital kidney anomalies and in 0.01% of population controls (odds ratio, 81.5; P=4.5×10−14). We localized the main drivers of renal disease in the DiGeorge syndrome to a 370-kb region containing nine genes. In zebrafish embryos, an induced loss of function in snap29, aifm3, and crkl resulted in renal defects; the loss of crkl alone was sufficient to induce defects. Five of 586 patients with congenital urinary anomalies had newly identified, heterozygous protein-altering variants, including a premature termination codon, in CRKL. The inactivation of Crkl in the mouse model induced developmental defects similar to those observed in patients with congenital urinary anomalies. CONCLUSIONS We identified a recurrent 370-kb deletion at the 22q11.2 locus as a driver of kidney defects in the DiGeorge syndrome and in sporadic congenital kidney and urinary tract anomalies. Of the nine genes at this locus, SNAP29, AIFM3, and CRKL appear to be critical to the phenotype, with haploinsufficiency of CRKL emerging as the main genetic driver. (Funded by the National Institutes of Health and others.)

BACKGROUND Congenital abnormalities of the kidney and the urinary tract are the most common cause of pediatric kidney failure. These disorders are highly heterogeneous, and the etiologic factors are poorly understood. METHODS We performed genomewide linkage analysis and whole-exome sequencing in a family with an autosomal dominant form of congenital abnormalities of the kidney or urinary tract (seven affected family members). We also performed a sequence analysis in 311 unrelated patients, as well as histologic and functional studies. RESULTS Linkage analysis identified five regions of the genome that were shared among all affected family members. Exome sequencing identified a single, rare, deleterious variant within these linkage intervals, a heterozygous splice-site mutation in the dual serine–threonine and tyrosine protein kinase gene (DSTYK). This variant, which resulted in aberrant splicing of messenger RNA, was present in all affected family members. Additional, independent DSTYK mutations, including nonsense and splice-site mutations, were detected in 7 of 311 unrelated patients. DSTYK is highly expressed in the maturing epithelia of all major organs, localizing to cell membranes. Knockdown in zebrafish resulted in developmental defects in multiple organs, which suggested loss of fibroblast growth factor (FGF) signaling. Consistent with this finding is the observation that DSTYK colocalizes with FGF receptors in the ureteric bud and metanephric mesenchyme. DSTYK knockdown in human embryonic kidney cells inhibited FGF-stimulated phosphorylation of extracellular-signal-regulated kinase (ERK), the principal signal downstream of receptor tyrosine kinases. CONCLUSIONS We detected independent DSTYK mutations in 2.3% of patients with congenital abnormalities of the kidney or urinary tract, a finding that suggests that DSTYK is a major determinant of human urinary tract development, downstream of FGF signaling. (Funded by the National Institutes of Health and others.)

Renal agenesis and hypodysplasia (RHD) are major causes of pediatric chronic kidney disease and are highly genetically heterogeneous. We conducted whole-exome sequencing in 202 case subjects with RHD and identified diagnostic mutations in genes known to be associated with RHD in 7/202 case subjects. In an additional affected individual with RHD and a congenital heart defect, we found a homozygous loss-of-function (LOF) variant in SLIT3, recapitulating phenotypes reported with Slit3 inactivation in the mouse. To identify genes associated with RHD, we performed an exome-wide association study with 195 unresolved case subjects and 6,905 control subjects. The top signal resided in GREB1L, a gene implicated previously in Hoxb1 and Shha signaling in zebrafish. The significance of the association, which was p = 2.0 × 10 for novel LOF, increased to p = 4.1 × 10 for LOF and deleterious missense variants combined, and augmented further after accounting for segregation and de novo inheritance of rare variants (joint p = 2.3 × 10). Finally, CRISPR/Cas9 disruption or knockdown of greb1l in zebrafish caused specific pronephric defects, which were rescued by wild-type human GREB1L mRNA, but not mRNA containing alleles identified in case subjects. Together, our study provides insight into the genetic landscape of kidney malformations in humans, presents multiple candidates, and identifies SLIT3 and GREB1L as genes implicated in the pathogenesis of RHD.

Methods Data on children hospitalized due to intoxication were retrieved from hospital medical records. Children were classified into 4 age groups: 0-5, 6-9, 10-13, and 14-18 years, and their sex and type of intoxication were recorded. For children with alcohol intoxication, data on time of intoxication, reason for drinking, presence of injuries or suspected suicide attempts, and possible presence of other drugs in the organism were collected.Results Out of 29 506 hospitalized children, 594 were hospitalized due to intoxications. Out of these, 239 (40.2%) were hospitalized due to intoxication by alcohol. More boys than girls were hospitalized (71.1%). The proportion of alcohol intoxication cases among all types of intoxication cases increased from 16.7% in 1997/98 to 66.3% in 2006/07. The proportion of patients hospitalized due to alcohol intoxication increased from 0.3% of all hospitalized children in the first year to 1.7% in the last year of the study (P = 0.015, z test for comparison of two proportions). Eighty two per cent of alcohol intoxication cases were in the 14-18 age-group. The number of alcohol intoxication cases increased among girls from 1 case (6.3% of all intoxication cases among girls) in 1997/98 to 15 cases (45.5%) in 2006/07, while among boys it increased from 6 cases (23.1% of all intoxicated boys) in 1997/98 to 44 cases (78.6%) in 2006/07. Children usually drank outside their homes (79.4%) and mostly on weekends and holidays (73.2%). ConclusionThe alarming increase in the number of hospitalizations due to alcohol intoxication in children, especially among girls and in the adolescent age group, represents a serious problem, which requires further attention and research. Clinical intoxication is a condition characterized by sudden or gradual threat to one or more organic systems due to contact with poison (1). Acute intoxications are often urgent situations that require a specific medical procedure. The first signs of acute alcohol intoxication in terms of behavior changes appear when the concentration of ethanol in serum reaches approximately 0.5‰ (1). When the concentration rises to 2.5‰, mydriasis, diplopia, ataxia, hypothermia, nausea, and vomiting appear (1). Concentration over 4.5‰ can lead to disorders of consciousness (sopor to coma), as well as to death due to respiratory insufficiency. Hypothermia often coexists with the described symptoms (1). The development of chronic alcoholism in adults lasts 5-10 years (2). Therefore, the term "alcoholism" cannot be applied to children, but we rather use the term "problems with alcohol. " The term includes all children who have social, psychological, or legal problems due to acute intoxication or regular excessive alcohol abuse or dependence (2).Alcohol intoxication is a growing phenomenon all over the world, which develops independently of the political, economical, social, and health care situation in the country. Thus, alcoholism is a serious problem in many countries, such as the United States (3-6), Scandinavian countries (7,8), Switzerla...

Ciliogenesis in developing and post-natal human kidneys appears to influence cell proliferation and differentiation, apico-basal cell polarity, and tubular lumen formation. We have analyzed the appearance of primary cilia and differentiation of kidney cells in ten human conceptuses aged 6-22 weeks and in one 5-year-old kidney, using a double immunofluorescence labeling technique for α-tubulin, γ-tubulin, Oct-4, and Ki-67 and by electron microscopy. Immature forms of nephrons and ampullae were characterized by intense cell proliferation, which subsequently decreased during development. Primary cilia appeared on the surfaces of non-proliferating cells in developing nephrons, gradually increasing in length from 0.59 μm in renal vesicles to 0.81 μm in the S-forms of nephrons, ultimately reaching 3.04 μm in length in mature fetal and post-natal nephrons. Ciliary length increased from 0.59 μm in ampullae to 1.28 μm in post-natal collecting tubules. Mesenchymal to epithelial transformation of kidney cells coincided with the appearance of apico-basal polarity, both gap and tight junctions, and lumen formation. Up-regulation of Oct-4 expression correlated with the onset of kidney cell differentiation. Our results demonstrate the importance of proper primary cilia lengthening and Oct-4 expression for the normal development of fetal and post-natal kidneys and of apico-basal polarity for normal tubular lumen formation. Disturbances in these processes are associated with ciliopathies.

Background: Information about renal diseases in children is available from national registries of renal biopsies. Aim of the study was to compare the clinical presentation of glomerular diseases and tubulointerstitial space diseases with pathohistological diagnosis of indicated renal biopsies from pediatric population in the Croatian region of Dalmatia. Methods: Out of 231 pediatric patients with suspected glomerular and tubulointerstitial diseases, 54 underwent ultrasound-guided renal biopsy at University Hospital of Split. Kidney allograft biopsy, and re-biopsy were excluded. The biopsy sections were examined under light microscopy, immunofluorescence and electron microscopy. The data was reviewed to determine the pathohistological spectrum and clinicopathologic correlations. We retrospectively analyzed kidney biopsy data from 2008 to 2017 and compared them to that between 1995 and 2005.Results: The mean age of patients was 9.84 ± 5.4 years. Male:female ratio was 1.2:1. The main indications for biopsy were pure nephrotic syndrome without hematuria (25.9%), non-nephrotic proteinuria with haematuria (22.2%), nephritic syndrome with nephrotic proteinuria (18.5%), and isolated hematuria (16.7%). The most common pathohistological findings were IgA nephropathy (IgAN, 24.1%), minimal change disease (MCD, 16.7%), Henoch-Schönlein purpura glomerulonephritis (HSPN, 14.8%), Alport syndrome and focal segmental glomerulosclerosis (AS and FSGS, 11.1% each), tubulointerstitial nephritis and membranous glomerulopathy (TIN and MGN, 3.7% each), while other cases were diagnosed rarely. Conclusions:Changes in epidemiology of renal diseases in children between the analyzed periods showed an increasing trend of IgAN, MCD, HSPN, AS and FSGS, while mesangioproliferative glomerulonephritis (MesPGN) and endoproliferative glomerulonephritis (EDGN) showed a decreasing trend that can be explained with the new pathohistological classification.