A holistic approach to CAKUT (Congenital Anomalies of the Kidney and Urinary Tract)

The urinary tract malformations, today called CAKUT (Congenital Anomalies of the Kidney and Urinary Tract), include a range of morphological and/or functional abnormalities of the kidney and urinary tract diseases, apart from being the main cause of renal failure in children. The frequency of these birth defects is around 2% of pregnancies and many genetic syndromes may include CAKUT: about 500 of them have been described. The CAKUT concern localized alterations at different levels of the urinary system: hydronephrosis, vesicoureteral reflux, duplex collecting system, megaureter, kidney dysplasia. In the approach to the child with CAKUT it is important to identify a population at risk, distinguishing between CAKUT with and without clinical significance, applying a tailored approach to the individual patient, avoiding unnecessary investigations and treatments

News on pediatric urology

Pediatric urology is a pediatric speciality dedicated to the diagnosis and treatment of congenital and acquired genitourinary tract diseases. It is a speciality that is rapidly changing, thanks to the technological development that has been emerging in recent years. There have been important diagnostic and therapeutic news. Congenital anomalies of the kidneys and urinary tract (CAKUT) include various entities of structural malformations that result from defects in their morphogenesis. Clinical research and genetic studies on the origins of CAKUT are quickly evolving, with significant growth of high-quality research. Management goals of CAKUT include prevention of febrile urinary tract infections (UTIs) in newborns and toddles and renal injury, while minimizing the morbidity of treatment and follow-up. Treatment options include observation with or without continuous antibiotic prophylaxis (CAP) and surgical correction. Now, randomized controlled studies show that children with normal urinary tracts or low-grade vesicoureteral reflux (VUR) do not benefit from prophylaxis. All children with known mechanical or functional obstructions of the urinary tract are considered to have UTI. Functional obstruction often results from lower urinary tract dysfunction (LUTD) of either neurogenic or non-neurogenic origin and dilating VUR. The role of bladder and bowel dysfunction (BBD) in children with UTI and the long-term risk of renal scarring have shed new light on treatment strategies. Often it is BBD, rather than reflux, that causes UTI in children older than 2 years. Pediatric urology has evolved in recent years, with a greater focus on bladder and renal function, minimally invasive treatment, evidence-based interventions, and guideline adherence. Other topics in pediatric urology include urinary incontinence in children with special needs and the use of robot-assisted laparoscopic surgery (RALS) in children, with advantages over conventional laparoscopic surgery.   Proceedings of the 11th International Workshop on Neonatology and Satellite Meetings · Cagliari (Italy) · October 26th-31st, 2015 · From the womb to the adult Guest Editors: Vassilios Fanos (Cagliari, Italy), Michele Mussap (Genoa, Italy), Antonio Del Vecchio (Bari, Italy), Bo Sun (Shanghai, China), Dorret I. Boomsma (Amsterdam, the Netherlands), Gavino Faa (Cagliari, Italy), Antonio Giordano (Philadelphia, USA

Case histories of five years of neonatal urinary tract infections: practical aspects of treatment and the need for agreed-upon guidelines

Case series of urinary tract infection (UTI) in neonates (0 to 1 month of life) hospitalized in the neonatal care unit of Cagliari’s university hospital during a five-year period. The major findings of this study are the prevalence of the infections in the male sex, the very high sensitivity of leukocyte esterase in detecting UTI, a higher C reactive Protein (CRP) sensitivity and specificity in comparison with procalcitonin (PCT) among markers of pyelonephritis. Moreover E. coli demonstrated an elevated ampicillin resistance. The retrospective evaluation of the data has led to an improvement in preventive strategies and medical-therapeutic choices applied in our department for the management of UTI. In view of the lack of national and international guidelines for UTI in this specific period of life, our data will to contribute to establishing generally accepted treatment procedures in this age group

Gut microbiota and pediatric patients with spina bifida and neurogenic bowel dysfunction

Purpose: Gut microbiota has recently been recognized to be influenced by a broad range of pathologies. Alterations of gut microbiota are known as dysbiosis and have found to be related to chronic constipation, a condition which affects also pediatric patients with spina bifida (SB). Methods: In this study, gut microbiota richness and composition were investigated by 16S rRNA sequencing and bioinformatic analysis in 48 SB patients (mean age, 11.9 ± 4.8 years) with secondary neurogenic constipation and 32 healthy controls (mean age, 18.0 ± 9.6 years). The study also aimed at exploring eventual effects of laxatives and transanal irrigation (TAI) adopted by SB subjects to get relief from the symptoms of neurogenic constipation. Results: Collected data demonstrated that the microbiota richness of SB patients was significantly increased compared to healthy controls, with a higher number of dominant bacteria rather than rare species. The absence of SB condition was associated with taxa Coprococcus 2, with the species C. eutactus and Roseburia, Dialister, and the [Eubacterium] coprostanoligenes group. On the other hand, the SB patients displayed a different group of positively associated taxa, namely, Blautia, Collinsella, Intestinibacter, and Romboutsia genera, the [Clostridium] innocuum group, and Clostridium sensu stricto 1. Bifidobacterium and the [Eubacterium] hallii group were also found to be positively associated with SB gut microbiome. Conclusions: Among SB patients, the administration of laxatives and TAI did not negatively affect gut microbiota diversity and composition, even considering long-term use (up to 5 years) of TAI device

Rare single nucleotide and copy number variants and the etiology of congenital obstructive uropathy : implications for genetic diagnosis

Significance statement: Congenital obstructive uropathy (COU) is a prevalent human developmental defect with highly heterogeneous clinical presentations and outcomes. Genetics may refine diagnosis, prognosis, and treatment, but the genomic architecture of COU is largely unknown. Comprehensive genomic screening study of 733 cases with three distinct COU subphenotypes revealed disease etiology in 10.0% of them. We detected no significant differences in the overall diagnostic yield among COU subphenotypes, with characteristic variable expressivity of several mutant genes. Our findings therefore may legitimize a genetic first diagnostic approach for COU, especially when burdening clinical and imaging characterization is not complete or available. Background: Congenital obstructive uropathy (COU) is a common cause of developmental defects of the urinary tract, with heterogeneous clinical presentation and outcome. Genetic analysis has the potential to elucidate the underlying diagnosis and help risk stratification. Methods: We performed a comprehensive genomic screen of 733 independent COU cases, which consisted of individuals with ureteropelvic junction obstruction ( n =321), ureterovesical junction obstruction/congenital megaureter ( n =178), and COU not otherwise specified (COU-NOS; n =234). Results: We identified pathogenic single nucleotide variants (SNVs) in 53 (7.2%) cases and genomic disorders (GDs) in 23 (3.1%) cases. We detected no significant differences in the overall diagnostic yield between COU sub-phenotypes, and pathogenic SNVs in several genes were associated to any of the three categories. Hence, although COU may appear phenotypically heterogeneous, COU phenotypes are likely to share common molecular bases. On the other hand, mutations in TNXB were more often identified in COU-NOS cases, demonstrating the diagnostic challenge in discriminating COU from hydronephrosis secondary to vesicoureteral reflux, particularly when diagnostic imaging is incomplete. Pathogenic SNVs in only six genes were found in more than one individual, supporting high genetic heterogeneity. Finally, convergence between data on SNVs and GDs suggest MYH11 as a dosage-sensitive gene possibly correlating with severity of COU. Conclusions: We established a genomic diagnosis in 10.0% of COU individuals. The findings underscore the urgent need to identify novel genetic susceptibility factors to COU to better define the natural history of the remaining 90% of cases without a molecular diagnosis

The copy number variation landscape of congenital anomalies of the kidney and urinary tract

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 (that is, 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; and 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

Author Correction: The copy number variation landscape of congenital anomalies of the kidney and urinary tract (Nature Genetics, (2019), 51, 1, (117-127), 10.1038/s41588-018-0281-y)

In the version of this article initially published, affiliation 38 incorrectly read “ICNU-Nephrology and Urology Department, Barcelona, Spain”; “Renal Division, Hospital Clinic, IDIBAPS, University of Barcelona, Barcelona, Spain” is the correct affiliation. The error has been corrected in the HTML and PDF versions of the article

The copy number variation landscape of congenital anomalies of the kidney and urinary tract.

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 (that is, 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; and 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