Genetics of human congenital urinary bladder disease

A genome-wide association study of antidepressant-induced mania

Antidepressant-induced mania (AIM) is a side effect of antidepressant treatment that is characterized by mania or hypomania after the start of medication. It is likely polygenic, but its genetic component remains largely unexplored. We aim to conduct the first genome-wide association study of AIM in 814 bipolar disorder patients of European ancestry. We report no significant findings from our single-marker or gene-based analyses. Our polygenic risk score analyses also did not yield significant results with bipolar disorder, antidepressant response, or lithium response. Our suggestive findings on the hypothalamic-pituitary-adrenal axis and the opioid system in AIM require independent replications.

Exstrophy-epispadias complex: are the kidneys and kidney function spared?

BACKGROUND

Exstrophy-epispadias complex (EEC) is a complex malformation of the lower abdominal wall, bladder, and pelvic floor, which necessitates multiple successive reconstruction procedures. Surgical and infectious complications are frequent. Our aim was to evaluate kidney function in these patients.

METHODS

This cross-sectional study included patients with EEC, followed since birth in a pediatric urology clinic, who underwent nephrological evaluation (blood pressure (BP) measurement and blood and urine chemistries) and imaging studies (urinary tract ultrasound and DMSA kidney scan) during 2017-2020.

RESULTS

Forty-three patients (29 males), median age 9 years (interquartile range 6-19), were included. Eleven (26%) used clean intermittent catheterization (CIC) for bladder drainage. At least one sign of kidney injury was identified in 32 (74%) patients; elevated BP, decreased kidney function (estimated glomerular filtration rate (eGFR) < 90 ml/min/1.73 m2), and proteinuria/albuminuria were detected in 29%, 12%, and 36% of patients, respectively. Urinary tract dilatation (UTD) was found in 13 (37%) ultrasound examinations. Parenchymal kidney defects were suspected in 46% and 61% of ultrasound and DMSA scintigraphy, respectively. UTD was significantly associated with DMSA-proven kidney defects (p = 0.043) and with elevated BP, 39% vs. 20% in those without UTD. Decreased eGFR and elevated BP were less frequent among patients on CIC than among patients who voided spontaneously: 10% vs. 14% and 18% vs. 36%, respectively. Recurrent UTIs/bacteriuria and nephro/cystolithiasis were reported by 44% and 29% patients, respectively.

CONCLUSION

The high rate of signs of kidney injury in pediatric patients with EEC dictates early-onset long-term kidney function monitoring by joint pediatric urological and nephrological teams. A higher resolution version of the Graphical abstract is available as Supplementary information.

Urinary Tract Dilation in the Fetus and Neonate

Urinary tract dilation (UTD), previously known as hydronephrosis, is the most common congenital condition identified on prenatal ultrasonography. UTD can be physiologic and resolve spontaneously or can be caused by various congenital anomalies of the urinary tract, which can lead to renal failure if not treated properly. In 2014, a multidisciplinary consensus group established UTD definitions, a classification system, and a standardized scheme for perinatal evaluation. Various imaging modalities are available to help diagnose the cause of UTD in fetuses and neonates and to help identify those patients who may benefit from fetal or early postnatal intervention. In this article, we will review the diagnosis and quantification of antenatal and postnatal UTD based on the UTD classification system, outline the imaging studies available to both evaluateUTD and determine its cause, briefly review the most common causes of UTD in the fetus and neonate, outline management strategies for UTD including the role for fetal intervention and prophylactic antibiotics, and report on the outcome and prognosis in patients with UTD.

Prune-belly syndrome in Africa: An analysis and systematic review of cases, etiology, treatment, and outcomes

Background:

Prune-belly syndrome is a rare congenital disorder characterized by a spectrum of three anomalies: bilateral undescended testes, dilated urinary tract, and anterior abdominal muscle deficiency.

Objectives:

In developing countries, inadequate access to health care may affect treatment and outcomes of prune-belly syndrome. This study’s goal was to review the anatomical features, etiology, genetics, management, and outcomes of cases in Africa.

Methods:

PubMed was searched to identify case reports and case studies describing prune-belly syndrome in Africa. Data collected from each study included the number of cases, age at diagnosis, sex, description of the abdominal muscles, testes, and urinary tract, as well as associated anomalies, management, and long-term outcomes.

Results:

A total of 16 publications that reported 58 cases in African countries were included. The prevalence of female patients (15.5%) was higher than in developed countries (3%). The abdominal muscles were deficient in all cases, and bilateral cryptorchidism was present in nearly all males (96%). Distension of the bladder was common, with normal anatomy reported in only one case. Bilateral hydroureters and hydronephrosis also were present in the majority of cases. Only six cases (10.3%) had no associated anomalies, such as musculoskeletal or cardiovascular. Karyotyping was performed in only three cases (5.2%) because of limited hospital facilities. Six parents (10.3%) declined treatment for their children, 12 cases (20.7%) were managed conservatively, and 25 (43.1%) received surgical intervention. Patients’ mortality rate was higher than in developed countries.

Conclusion:

Diagnosis and treatment of prune-belly syndrome remains a challenge in Africa, in which multiple factors, such as access to health care and cultural beliefs, affect mortality rates and outcomes. Patient education and support groups may improve compliance with treatment.

Level of evidence:

Not applicable for this multicenter audit.

Congenital Disorders of the Human Urinary Tract: Recent Insights From Genetic and Molecular Studies

The urinary tract comprises the renal pelvis, the ureter, the urinary bladder, and the urethra. The tract acts as a functional unit, first propelling urine from the kidney to the bladder, then storing it at low pressure inside the bladder which intermittently and completely voids urine through the urethra. Congenital diseases of these structures can lead to a range of diseases sometimes associated with fetal losses or kidney failure in childhood and later in life. In some of these disorders, parts of the urinary tract are severely malformed. In other cases, the organs appear grossly intact yet they have functional deficits that compromise health. Human studies are beginning to indicate monogenic causes for some of these diseases. Here, the implicated genes can encode smooth muscle, neural or urothelial molecules, or transcription factors that regulate their expression. Furthermore, certain animal models are informative about how such molecules control the development and functional differentiation of the urinary tract. In future, novel therapies, including those based on gene transfer and stem cell technologies, may be used to treat these diseases to complement conventional pharmacological and surgical clinical therapies.

An adolescent boy progressing insidiously to end-stage renal disease: Answers

Hinman syndrome was a non-neurogenic neurogenic bladder and the most severe form of dysfunctional voiding disorder. The bladder-sphincter discoordination causes damage to the bladder and upper urinary tract if it is not diagnosed early and treated adequately. This case emphasizes the following important message: nighttime wetting is not a benign condition in every child. Parental awareness should be raised about voiding disorders, as it may be possible to prevent important renal diseases such as Hinman syndrome.

From gene discovery to new biological mechanisms: heparanases and congenital urinary bladder disease

We present a scientific investigation into the pathogenesis of a urinary bladder disease. The disease in question is called urofacial syndrome (UFS), a congenital condition inherited in an autosomal recessive manner. UFS features incomplete urinary bladder emptying and vesicoureteric reflux, with a high risk of recurrent urosepsis and end-stage renal disease. The story starts from a human genomic perspective, then proceeds through experiments that seek to determine the roles of the implicated molecules in embryonic frogs and newborn mice. A future aim would be to use such biological knowledge to intelligently choose novel therapies for UFS. We focus on heparanase proteins and the peripheral nervous system, molecules and tissues that appear to be key players in the pathogenesis of UFS and therefore must also be critical for functional differentiation of healthy bladders. These considerations allow the envisioning of novel biological treatments, although the potential difficulties of targeting the developing bladder in vivo should not be underestimated.

Pathology of the stillborn infant for the general pathologist: part 1

As the information obtained from previable fetal and stillbirth autopsies is used not only to explain the loss to the parents, but for future pregnancy planning, general pathologists need to be comfortable in dealing with these autopsies. The importance of an adequate fetal examination has been emphasized in a recent policy on the subject by the American Board of Pathology http://www.abpath.org/FetalAutopsyPolicy.pdf. This review paper covers the approach to the fetal and stillbirth autopsy. This first article covers the approach to the nonanomalous and anomalous autopsy. Hydrops fetalis will be covered in the second part of this series to be published subsequently.

Single-gene causes of congenital anomalies of the kidney and urinary tract (CAKUT) in humans

Congenital anomalies of the kidney and urinary tract (CAKUT) cover a wide range of structural malformations that result from defects in the morphogenesis of the kidney and/or urinary tract. These anomalies account for about 40-50 % of children with chronic kidney disease worldwide. Knowledge from genetically modified mouse models suggests that single gene mutations in renal developmental genes may lead to CAKUT in humans. However, until recently, only a handful of CAKUT-causing genes were reported, most of them in familial syndromic cases. Recent findings suggest that CAKUT may arise from mutations in a multitude of different single gene causes. We focus here on single-gene causes of CAKUT and their developmental origin. Currently, more than 20 monogenic CAKUT-causing genes have been identified. High-throughput sequencing techniques make it likely that additional CAKUT-causing genes will be identified in the near future.

Urofacial syndrome: a genetic and congenital disease of aberrant urinary bladder innervation

The urofacial, or Ochoa, syndrome is characterised by congenital urinary bladder dysfunction together with an abnormal grimace upon smiling, laughing and crying. It can present as fetal megacystis. Postnatal features include urinary incontinence and incomplete bladder emptying due to simultaneous detrusor muscle and bladder outlet contractions. Vesicoureteric reflux is often present, and the condition can be complicated by urosepsis and end-stage renal disease. The syndrome has long been postulated to have neural basis, and it can be familial when it is inherited in an autosomal recessive manner. Most individuals with urofacial syndrome genetically studied to date carry biallelic, postulated functionally null mutations of HPSE2 or, less commonly, of LRIG2. Little is known about the biology of the respective encoded proteins, heparanase 2 and leucine-rich repeats and immunoglobulin-like domains 2. Nevertheless, the observations that heparanase 2 can bind heparan sulphate proteolgycans and inhibit heparanase 1 enzymatic activity and that LRIG2 can modulate receptor tyrosine kinase growth factor signalling each point to biological roles relevant to tissue differentiation. Moreover, both heparanase 2 and LRIG2 proteins are detected in autonomic nerves growing into fetal bladders. The collective evidence is consistent with the hypothesis that urofacial syndrome genes code for proteins which work in a common pathway to facilitate neural growth into, and/or function within, the bladder. This molecular pathway may also have relevance to our understanding of the pathogenesis of other lower tract diseases, including Hinman-Allen syndrome, or non-neurogenic neurogenic bladder, and of the subset of individuals who have primary vesicoureteric reflux accompanied by bladder dysfunction.