Kidney function and transplants in prune belly syndrome: a scoping review.

BACKGROUND: Children with prune belly syndrome (PBS) are at higher risk of developing kidney dysfunction and requiring kidney replacement therapy (KRT). While studies have described surgical and survival outcomes in these populations, there has yet to be a focused synthesis of evidence regarding kidney outcomes in this population. Here, the focus of this scoping review was to highlight knowledge gaps and report standards on kidney outcomes in PBS of all ages. METHODS: Following scoping review methodology, EMBASE, MEDLINE, and Scopus were searched for peer-reviewed literature that describe kidney outcomes in PBS. All studies with a broad set of kidney outcomes (such as kidney function measures, chronic kidney disease (CKD), KRT and associated outcomes) were included. Findings were summarized and qualitatively synthesized. RESULTS: Of the 436 unique records identified, 25 were included for synthesis. A total of 17 studies (441 patients) reported on kidney insufficiency outcomes, with an estimated prevalence of CKD ranging from 8 to 66%. A total of 15 studies (314 patients) described KRT, primary kidney transplant, and outcomes. Of these, the age for KRT ranged from 4 to 21 years, and graft survival ranged from 22 to 87% by last follow-up (range 1.3-27 years). CONCLUSIONS: There is significant variability in studies reporting kidney outcomes in PBS which limits meaningful synthesis. There is a need for future studies with comprehensive reporting of confounders and drivers for kidney insufficiency in PBS.

The utility of gene sequencing in identifying an underlying genetic disorder in prenatally suspected lower urinary tract obstruction.

OBJECTIVE: Fetal megacystis generally presents as suspected lower urinary tract obstruction (LUTO), which is associated with severe perinatal morbidity. Genetic etiologies underlying LUTO or a LUTO-like initial presentation are poorly understood. Our objectives are to describe single gene etiologies in fetuses initially ascertained to have suspected LUTO and to elucidate genotype-phenotype correlations. METHODS: A retrospective case series of suspected fetal LUTO positive for a molecular diagnosis was collected from five centers in the Fetal Sequencing Consortium. Demographics, sonograms, genetic testing including variant classification, and delivery outcomes were abstracted. RESULTS: Seven cases of initially prenatally suspected LUTO-positive for a molecular diagnosis were identified. In no case was the final diagnosis established as urethral obstruction that is, LUTO. All variants were classified as likely pathogenic or pathogenic. Smooth muscle deficiencies involving the bladder wall and interfering with bladder emptying were identified in five cases: MYOCD (2), ACTG2 (2), and MYH11 (1). Other genitourinary and/or non-genitourinary malformations were seen in two cases involving KMT2D (1) and BBS10 (1). CONCLUSION: Our series illustrates the value of molecular diagnostics in the workup of fetuses who present with prenatally suspected LUTO but who may have a non-LUTO explanation for their prenatal ultrasound findings.

Urethral luminal epithelia are castration-insensitive cells of the proximal prostate.

BACKGROUND: Castration-insensitive epithelial progenitors capable of regenerating the prostate have been proposed to be concentrated in the proximal region based on facultative assays. Functional characterization of prostate epithelial populations isolated with individual cell surface markers has failed to provide a consensus on the anatomical and transcriptional identity of proximal prostate progenitors. METHODS: Here, we use single-cell RNA sequencing to obtain a complete transcriptomic profile of all epithelial cells in the mouse prostate and urethra to objectively identify cellular subtypes. Pan-transcriptomic comparison to human prostate cell types identified a mouse equivalent of human urethral luminal cells, which highly expressed putative prostate progenitor markers. Validation of the urethral luminal cell cluster was performed using immunostaining and flow cytometry. RESULTS: Our data reveal that previously identified facultative progenitors marked by Trop2, Sca-1, KRT4, and PSCA are actually luminal epithelial cells of the urethra that extend into the proximal region of the prostate, and are resistant to castration-induced androgen deprivation. Mouse urethral luminal cells were identified to be the equivalent of previously identified human club and hillock cells that similarly extend into proximal prostate ducts. Benign prostatic hyperplasia (BPH) has long been considered an "embryonic reawakening," but the cellular origin of the hyperplastic growth concentrated in the periurethral region is unclear. We demonstrate an increase in urethral luminal cells within glandular nodules from BPH patients. Urethral luminal cells are further increased in patients treated with a 5-α reductase inhibitor. CONCLUSIONS: Our data demonstrate that cells of the proximal prostate that express putative progenitor markers, and are enriched by castration in the proximal prostate, are urethral luminal cells and that these cells may play an important role in the etiology of human BPH.

Prune belly syndrome in surviving males can be caused by Hemizygous missense mutations in the X-linked Filamin A gene.

BACKGROUND: Prune belly syndrome (PBS) is a rare, multi-system congenital myopathy primarily affecting males that is poorly described genetically. Phenotypically, its morbidity spans from mild to lethal, however, all isolated PBS cases manifest three cardinal pathological features: 1) wrinkled flaccid ventral abdominal wall with skeletal muscle deficiency, 2) urinary tract dilation with poorly contractile smooth muscle, and 3) intra-abdominal undescended testes. Despite evidence for a genetic basis, previously reported PBS autosomal candidate genes only account for one consanguineous family and single cases. METHODS: We performed whole exome sequencing (WES) of two maternal adult half-brothers with syndromic PBS (PBS + Otopalatodigital spectrum disorder [OPDSD]) and two unrelated sporadic individuals with isolated PBS and further functionally validated the identified mutations. RESULTS: We identified three unreported hemizygous missense point mutations in the X-chromosome gene Filamin A (FLNA) (c.4952 C > T (p.A1448V), c.6727C > T (p.C2160R), c.5966 G > A (p.G2236E)) in two related cases and two unrelated sporadic individuals. Two of the three PBS mutations map to the highly regulatory, stretch-sensing Ig19-21 region of FLNA and enhance binding to intracellular tails of the transmembrane receptor ß-integrin 1 (ITGß1). CONCLUSIONS: FLNA is a regulatory actin-crosslinking protein that functions in smooth muscle cells as a mechanosensing molecular scaffold, transmitting force signals from the actin-myosin motor units and cytoskeleton via binding partners to the extracellular matrix. This is the first evidence for an X-linked cause of PBS in multiple unrelated individuals and expands the phenotypic spectrum associated with FLNA in males surviving even into adulthood.

Phenotypic severity scoring system and categorisation for prune belly syndrome: application to a pilot cohort of 50 living patients.

OBJECTIVE: To design a novel system of scoring prune belly syndrome (PBS) phenotypic severity at any presenting age and apply it to a large pilot cohort. PATIENTS AND METHODS: From 2000 to 2017, patients with PBS were recruited to our prospective PBS study and medical records were cross-sectionally analysed, generating individualised RUBACE scores. We designed the pragmatic RUBACE-scoring system based on six sub-scores (R: renal, U: ureter, B: bladder/outlet, A: abdominal wall, C: cryptorchidism, E: extra-genitourinary, generating the acronym RUBACE), yielding a potential summed score of 0-31. The 'E' score was used to segregate syndromic PBS and PBS-plus variants. The cohort was scored per classic Woodard criteria and RUBACE scores compared to Woodard category. RESULTS: In all, 48 males and two females had a mean (range) RUBACE score of 13.8 (8-25) at a mean age of 7.3 years. Segregated by phenotypic categories, there were 39 isolated PBS (76%), six syndromic PBS (12%) and five PBS-plus (10%) cases. The mean RUBACE scores for Woodard categories 1, 2, and 3 were 20.5 (eight patients), 13.8 (25), and 10.6 (17), respectively (P < 0.001). CONCLUSIONS: RUBACE is a practical, organ/system level, phenotyping tool designed to grade PBS severity and categorise patients into isolated PBS, syndromic PBS, and PBS-plus groups. This standardised system will facilitate genotype-phenotype correlations and future prospective multicentre studies assessing medical and surgical treatment outcomes.

Straight to the Operating Room: An Emergent Surgery Track for Acute Testicular Torsion Transfers.

OBJECTIVE: To assess the effect of implementing an emergency surgery track for testicular torsion transfers. We hypothesized that transferring children from other facilities diagnosed with torsion straight to the operating room (STOR) would decrease ischemia time, lower costs, and reduce testicular loss. STUDY DESIGN: Demographics, arrival to incision time, hospital cost in dollars, and testicular outcome (determined by testicular ultrasound) at follow-up were retrospectively compared in all patients transferred to our tertiary care children's hospital with a diagnosis of testicular torsion from 2012 to 2016. Clinical data for STOR and non-STOR patients were compared by Wilcoxon rank-sum, 2-tailed t test, or Fisher exact test as appropriate. RESULTS: Sixty-eight patients met inclusion criteria: 35 STOR and 33 non-STOR. Children taken STOR had a shorter median arrival to incision time (STOR: 54 minutes vs non-STOR: 94 minutes, P < .0001) and lower median total hospital costs (STOR: $3882 vs non-STOR: $4419, P < .0001). However, only 46.8% of STOR patients and 48.4% of non-STOR patients achieved surgery within 6 hours of symptom onset. Testicular salvage rates in STOR and non-STOR patients were not significantly different (STOR: 68.4% vs non-STOR: 36.8%, P = .1), but follow-up was poor. CONCLUSIONS: STOR decreased arrival to incision time and hospital cost but did not affect testicular loss. The bulk of ischemia time in torsion transfers occurred before arrival at our tertiary care center. Further interventions addressing delays in diagnosis and transfer are needed to truly improve testicular salvage rates in these patients.

Copy number variations in a population with prune belly syndrome.

Prune Belly Syndrome (PBS) is a congenital multisystem myopathy with mild to lethal severity. While of uncertain etiology, 95% male predominance and familial occurrence suggest a genetic basis. As copy number variations (CNVs) can cause unexplained genetic disorders, we tested for novel CNVs in a large PBS population. We genotyped 21 unrelated PBS patients by high-resolution array comparative genomic hybridization (aCGH) and phenotyped using a novel PBS severity scoring system. Available parents were screened for detected CNV via quantitative PCR (qPCR). We additionally screened for recurrence of identified novel candidate CNVs on 106 PBS probands by qPCR. We identified 10 CNVs in 8 of 21 PBS patients tested (38%). Testing confirmed inheritance from an unaffected biological parent in six patients; parental samples were unavailable in two probands. One candidate CNV includes duplication of the X-chromosome AGTR2 gene, known to function in urinary tract development. Subsequent screening of the larger PBS cohort did not identify any recurrent CNVs. Presence of CNV did not correlate with PBS severity scoring. CNVs were uncommon in this large PBS population, but analysis of identified variants may inform disease pathogenesis and reveal targets for therapeutic intervention for this rare, severe disorder.

Transscrotal Near Infrared Spectroscopy as a Diagnostic Test for Testis Torsion in Pediatric Acute Scrotum: A Prospective Comparison to Gold Standard Diagnostic Test Study.

PURPOSE: A rapid test for testicular torsion in children may obviate the delay for testicular ultrasound. In this study we assessed testicular tissue percent oxygen saturation (%StO2) measured by transscrotal near infrared spectroscopy as a diagnostic test for pediatric testicular torsion. MATERIALS AND METHODS: This was a prospective comparison to a gold standard diagnostic test study that evaluated near infrared spectroscopy %StO2 readings to diagnose testicular torsion. The gold standard for torsion diagnosis was standard clinical care. From 2013 to 2015 males with acute scrotum for more than 1 month and who were less than 18 years old were recruited. Near infrared spectroscopy %StO2 readings were obtained for affected and unaffected testes. Near infrared spectroscopy Δ%StO2 was calculated as unaffected minus affected reading. The utility of near infrared spectroscopy Δ%StO2 to diagnose testis torsion was described with ROC curves. RESULTS: Of 154 eligible patients 121 had near infrared spectroscopy readings. Median near infrared spectroscopy Δ%StO2 in the 36 patients with torsion was 2.0 (IQR -4.2 to 9.8) vs -1.7 (IQR -8.7 to 2.0) in the 85 without torsion (p=0.004). AUC for near infrared spectroscopy as a diagnostic test was 0.66 (95% CI 0.55-0.78). Near infrared spectroscopy Δ%StO2 of 20 or greater had a positive predictive value of 100% and a sensitivity of 22.2%. Tanner stage 3-5 cases without scrotal edema or with pain for 12 hours or less had an AUC of 0.91 (95% CI 0.86-1.0) and 0.80 (95% CI 0.62-0.99), respectively. CONCLUSIONS: In all children near infrared spectroscopy readings had limited utility in diagnosing torsion. However, in Tanner 3-5 cases without scrotal edema or with pain 12 hours or less, near infrared spectroscopy discriminated well between torsion and nontorsion.

Medical and dietary interventions for preventing recurrent urinary stones in children.

BACKGROUND: Nephrolithiasis, or urinary stone disease, in children causes significant morbidity, and is increasing in prevalence in the North American population. Therefore, medical and dietary interventions (MDI) for recurrent urinary stones in children are poised to gain increasing importance in the clinical armamentarium. OBJECTIVES: To assess the effects of medical and dietary interventions (MDI) for the prevention of idiopathic urinary stones in children aged from one to 18 years. SEARCH METHODS: We searched multiple databases using search terms relevant to this review, including studies identified from the Cochrane Central Register of Controlled Trials (CENTRAL, 2017, Issue 1), MEDLINE OvidSP (1946 to 14 February 2017), Embase OvidSP (1980 to 14 February 2017), International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. Additionally, we handsearched renal-related journals and the proceedings of major renal conferences, and reviewed weekly current awareness alerts for selected renal journals. The date of the last search was 14 February 2017. There were no language restrictions. SELECTION CRITERIA: Randomized controlled trials of at least one year of MDI versus control for prevention of recurrent idiopathic (non-syndromic) nephrolithiasis in children. DATA COLLECTION AND ANALYSIS: We used standard methodologic procedures expected by Cochrane. Titles and abstracts were identified by search criteria and then screened for relevance, and then data extraction and risk of bias assessment were carried out. We assessed the quality of evidence using GRADE. MAIN RESULTS: The search identified one study of 125 children (72 boys and 53 girls) with calcium-containing idiopathic nephrolithiasis and normal renal morphology following initial treatment with shockwave lithotripsy (SWL). Patients were randomized to oral potassium citrate 1 mEq/kg per day for 12 months versus no specific medication or preventive measure with results reported for a total of 96 patients (48 per group). This included children who were stone-free (n = 52) or had residual stone fragments (n = 44) following SWL. Primary outcomes:Medical therapy may lower rates of stone recurrence with a risk ratio (RR) of 0.19 (95% confidence interval (CI) 0.06 to 0.60; low quality evidence). This corresponds to 270 fewer stone recurrences per 1000 (133 fewer to 313 fewer) children. We downgraded the quality of evidence by two levels for very serious study limitations related to unclear allocation concealment (selection bias) and a high risk of performance, detection and attrition bias. While the data for adverse events were incomplete, they reported that six of 48 (12.5%) children receiving potassium citrate left the trial because of adverse effects. This corresponds to a RR of 13.0 (95% CI 0.75 to 224.53; very low quality evidence); an absolute effect size estimate could not be generated. We downgraded the quality of evidence for study limitations and imprecision.We found no information on retreatment rates. SECONDARY OUTCOMES: We found no evidence on serum electrolytes, 24-hour urine collection parameters or time to new stone formation.We were unable to perform any preplanned secondary analyses. AUTHORS' CONCLUSIONS: Oral potassium citrate supplementation may reduce recurrent calcium urinary stone formation in children following SWL; however, our confidence in this finding is limited. A substantial number of children stopped the medication due to adverse events. There is no trial evidence on retreatment rates. There is a critical need for additional well-designed trials in children with nephrolithiasis.

Long-Term Outcomes of Bladder Neck Reconstruction without Augmentation Cystoplasty in Children.

PURPOSE: Bladder outlet procedures without augmentation cystoplasty remain controversial. We hypothesized that bladder outlet procedures without augmentation cystoplasty may lead to unfavorable bladder dynamics, upper tract changes and/or continued incontinence. We reviewed long-term urodynamic, upper tract and continence outcomes following bladder outlet procedures without augmentation cystoplasty. MATERIALS AND METHODS: We retrospectively reviewed all patients who underwent bladder neck reconstruction/closure/sling without augmentation cystoplasty between 2000 and 2014. Because of variation in length of followup, we calculated the cumulative incidence and proportion of cases of upper tract and urodynamic changes, augmentation cystoplasty and subsequent continence procedures. Preoperative factors were compared between patients with and without adverse outcomes. RESULTS: A total of 109 patients underwent bladder outlet procedures without augmentation cystoplasty at a mean age of 8.5 years. At a mean of 4.9 years of followup 59 patients (54%) had undergone additional continence surgery, 20 (18%) had undergone augmentation cystoplasty, 50 (46%) manifested vesicoureteral reflux or hydronephrosis and 23 (21%) had newly diagnosed or worsening renal scarring. At augmentation cystoplasty 13 of 18 patients (72%) had upper tract changes, 15 (83%) had continued incontinence and 11 (61%) had an end fill pressure of greater than 40 cm H2O. All patients had resolution of these changes after augmentation cystoplasty. Patients who had previously undergone vesicostomy or surgery for vesicoureteral reflux were significantly more likely to undergo a subsequent augmentation cystoplasty or to show upper tract changes. CONCLUSIONS: Following bladder outlet procedures without augmentation cystoplasty the estimated 10-year cumulative incidence of augmentation cystoplasty is 30%, continence procedures 70%, upper tract changes greater than 50% and chronic kidney disease 20%. Because of these risks, careful patient selection and close followup are essential if considering a bladder outlet procedure without augmentation cystoplasty.

Diagnosing Testicular Torsion before Urological Consultation and Imaging: Validation of the TWIST Score.

PURPOSE: The TWIST (Testicular Workup for Ischemia and Suspected Torsion) score uses urological history and physical examination to assess risk of testis torsion. Parameters include testis swelling (2 points), hard testis (2), absent cremasteric reflex (1), nausea/vomiting (1) and high riding testis (1). While TWIST has been validated when scored by urologists, its diagnostic accuracy among nonurological providers is unknown. We assessed the usefulness of the TWIST score when determined by nonurological nonphysician providers, mirroring emergency room evaluation of acute scrotal pain. MATERIALS AND METHODS: Children with unilateral acute scrotum were prospectively enrolled in a National Institutes of Health clinical trial. After undergoing basic history and physical examination training, emergency medical technicians calculated TWIST score and determined Tanner stage per pictorial diagram. Clinical torsion was confirmed by surgical exploration. All data were captured into REDCap™ and ROC curves were used to evaluate the diagnostic usefulness of TWIST. RESULTS: Of 128 patients (mean age 11.3 years) 44 (13.0 years) had torsion. TWIST score cutoff values of 0 and 6 derived from ROC analysis identified 31 high, 57 intermediate and 40 low risk cases (positive predictive value 93.5%, negative predictive value 100%). CONCLUSIONS: TWIST score assessed by nonurologists, such as emergency medical technicians, is accurate. Low risk patients do not require ultrasound to rule out torsion. High risk patients can proceed directly to surgery, with more than 50% avoiding ultrasound. In the future emergency medical technicians and/or emergency room triage personnel may be able to calculate TWIST score to guide radiological evaluation and immediate surgical intervention at initial assessment long before urological consultation.

Reprogramming of human fibroblasts toward a cardiac fate.

Reprogramming of mouse fibroblasts toward a myocardial cell fate by forced expression of cardiac transcription factors or microRNAs has recently been demonstrated. The potential clinical applicability of these findings is based on the minimal regenerative potential of the adult human heart and the limited availability of human heart tissue. An initial but mandatory step toward clinical application of this approach is to establish conditions for conversion of adult human fibroblasts to a cardiac phenotype. Toward this goal, we sought to determine the optimal combination of factors necessary and sufficient for direct myocardial reprogramming of human fibroblasts. Here we show that four human cardiac transcription factors, including GATA binding protein 4, Hand2, T-box5, and myocardin, and two microRNAs, miR-1 and miR-133, activated cardiac marker expression in neonatal and adult human fibroblasts. After maintenance in culture for 4-11 wk, human fibroblasts reprogrammed with these proteins and microRNAs displayed sarcomere-like structures and calcium transients, and a small subset of such cells exhibited spontaneous contractility. These phenotypic changes were accompanied by expression of a broad range of cardiac genes and suppression of nonmyocyte genes. These findings indicate that human fibroblasts can be reprogrammed to cardiac-like myocytes by forced expression of cardiac transcription factors with muscle-specific microRNAs and represent a step toward possible therapeutic application of this reprogramming approach.

DNA copy number variations in patients with persistent cloaca.

PURPOSE: Persistent cloaca is a devastating female anomaly associated with renal insufficiency/failure, urinary and fecal incontinence and müllerian dysfunction. Genetically engineered murine models of persistent cloaca suggest that this anomaly could have a genetic component in humans. Genomic copy number variations account for previously unexplained genetic diseases by identifying candidate genes in various disorders. We assessed whether novel copy number variations are present in patients with persistent cloaca. MATERIALS AND METHODS: With institutional review board approval we performed a retrospective chart review to identify patients with persistent cloaca. Lymphocyte DNA was prospectively tested by whole genome array comparative genomic hybridization. HHAT was Sanger sequenced from genomic DNA. RESULTS: At study recruitment mean age was 12 years (range 0.5 to 23) in 17 females with cloaca. Seven females (41%) had a solitary functioning kidney and 2 each had renal insufficiency and renal replacement therapy. The common cloaca channel was 1.5 to 6 cm long in 6 newborns. Six patients (35%) had vaginal duplication and 4 had spinal anomalies. Array comparative genomic hybridization revealed copy number variations in 7 patients (41%), including 5 gains and 2 losses. Two copy number variations were novel, including a paternally inherited duplication on 16p13.2 and a de novo deletion on 1q32.1q32.3. Subsequent sequencing of the candidate gene HHAT identified no causal mutations. CONCLUSIONS: Persistent cloaca is a rare but morbid birth defect. Copy number variations are common in these females but HHAT mutations are not common. Further investigation of these genomic rearrangements may lead to the identification of genetic causes of persistent cloaca.

DNA copy number variations in patients with 46,XY disorders of sex development.

PURPOSE: Less than 50% of cases of 46,XY disorders of sex development are genetically defined after karyotyping and/or sequencing of known causal genes. Since copy number variations are often missed by karyotyping and sequencing, we assessed patients with unexplained 46,XY disorders of sex development using array comparative genomic hybridization for possible disease causing genomic variants. MATERIALS AND METHODS: DNA from unexplained cases of 46,XY disorders of sex development were tested by whole genome array comparative genomic hybridization. In cases where novel copy number variations were detected parental testing was performed to identify whether copy number variations were de novo or inherited. RESULTS: Of the 12 patients who underwent array comparative genomic hybridization testing 2 had possible copy number variations causing disorders of sex development, both maternally inherited microdeletions. One case, with a maternal history of premature ovarian failure, had a cosegregating microdeletion on 9q33.3 involving NR5A1. The other case, with a maternal family history of congenital heart disease, had a cosegregating microdeletion on 8p23.1 upstream of GATA4. CONCLUSIONS: In this cohort copy number variations involving or adjacent to known causal genes led to 46,XY disorders of sex development in 2 of 12 previously unexplained cases (17%). Copy number variation testing is clinically indicated for unexplained cases of 46,XY disorders of sex development to aid in genetic counseling for family planning.

Evaluation and treatment of cryptorchidism: AUA guideline.

PURPOSE: Cryptorchidism is one of the most common pediatric disorders of the male endocrine glands and the most common genital disorder identified at birth. This guideline is intended to provide physicians and non-physician providers (primary care and specialists) with a consensus of principles and treatment plans for the management of cryptorchidism (typically isolated non-syndromic). MATERIALS AND METHODS: A systematic review and meta-analysis of the published literature was conducted using controlled vocabulary supplemented with key words relating to the relevant concepts of cryptorchidism. The search strategy was developed and executed by reference librarians and methodologists to create an evidence report limited to English-language, published peer-reviewed literature. This review yielded 704 articles published from 1980 through 2013 that were used to form a majority of the guideline statements. Clinical Principles and Expert Opinions were used for guideline statements lacking sufficient evidence-based data. RESULTS: Guideline statements were created to inform clinicians on the proper methods of history-taking, physical exam, and evaluation of the boy with cryptorchidism, as well as the various hormonal and surgical treatment options. CONCLUSIONS: Imaging for cryptorchidism is not recommended prior to referral, which should occur by 6 months of age. Orchidopexy (orchiopexy is the preferred term) is the most successful therapy to relocate the testis into the scrotum, while hormonal therapy is not recommended. Successful scrotal repositioning of the testis may reduce but does not prevent the potential long-term issues of infertility and testis cancer. Appropriate counseling and follow-up of the patient is essential.

The use of autologous buccal mucosa grafts in vaginal reconstruction.

Vaginal reconstruction can be challenging when there is a paucity of tissue, as the ideal donor source has yet to be determined. Many of the existing and commonly used techniques, such as vaginal replacement with skin grafts or bowel segments, have both advantages and disadvantages. A novel technique for vaginal replacement and reconstruction is with autologous buccal mucosa, an epithelium which is an excellent tissue match to the vagina. As urologists often have extensive experience with the use of oral mucosa for urethral reconstruction, it is fitting to apply these techniques to procedures where native vaginal tissue is lacking. This review presents the existing literature as well as the author's own experience with the use of autologous buccal mucosa for a variety of vaginal reconstructive procedures.

Autologous buccal mucosa graft for repair of recurrent rectovaginal fistula.

Post-operative pediatric rectovaginal fistulas are rare, can be challenging to repair, and often recur. The versatility, ease of accessibility, vascularization, and likeness to native vaginal tissues make autologous buccal mucosal grafts a novel tissue substitute for the repair of a recurrent rectovaginal fistula after the surgical repair of anorectal malformations.

PIEZO1 loss-of-function compound heterozygous mutations in the rare congenital human disorder Prune Belly Syndrome.

Prune belly syndrome (PBS), also known as Eagle-Barret syndrome, is a rare, multi-system congenital myopathy primarily affecting males. Phenotypically, PBS cases manifest three cardinal pathological features: urinary tract dilation with poorly contractile smooth muscle, wrinkled flaccid ventral abdominal wall with skeletal muscle deficiency, and intra-abdominal undescended testes. Genetically, PBS is poorly understood. After performing whole exome sequencing in PBS patients, we identify one compound heterozygous variant in the PIEZO1 gene. PIEZO1 is a cation-selective channel activated by various mechanical forces and widely expressed throughout the lower urinary tract. Here we conduct an extensive functional analysis of the PIEZO1 PBS variants that reveal loss-of-function characteristics in the pressure-induced normalized open probability (NPo) of the channel, while no change is observed in single-channel currents. Furthermore, Yoda1, a PIEZO1 activator, can rescue the NPo defect of the PBS mutant channels. Thus, PIEZO1 mutations may be causal for PBS and the in vitro cellular pathophysiological phenotype could be rescued by the small molecule, Yoda1. Activation of PIEZO1 might provide a promising means of treating PBS and other related bladder dysfunctional states.

Genetic abnormalities in FOXP1 are associated with congenital heart defects.

The etiology for the majority of congenital heart defects (CHD) is unknown. We identified a patient with unbalanced atrioventricular septal defect (AVSD) and hypoplastic left ventricle who harbored an ~0.3 Mb monoallelic deletion on chromosome 3p14.1. The deletion encompassed the first four exons of FOXP1, a gene critical for normal heart development that represses cardiomyocyte proliferation and expression of Nkx2.5. To determine whether FOXP1 mutations are found in patients with CHD, we sequenced FOXP1 in 82 patients with AVSD or hypoplastic left heart syndrome. We discovered two patients who harbored a heterozygous c.1702C>T variant in FOXP1 that predicted a potentially deleterious substitution of a highly conserved proline (p.Pro568Ser). This variant was not found in 287 controls but is present in dbSNP at a 0.2% frequency. The orthologous murine Foxp1 p.Pro596Ser mutant protein displayed deficits in luciferase reporter assays and resulted in increased proliferation and Nkx2.5 expression in cardiomyoblasts. Our data suggest that haploinsufficiency of FOXP1 is associated with human CHD.

Screening and familial characterization of copy-number variations in NR5A1 in 46,XY disorders of sex development and premature ovarian failure.

The NR5A1 gene encodes for steroidogenic factor 1, a nuclear receptor that regulates proper adrenal and gonadal development and function. Mutations identified by NR5A1 sequencing have been associated with disorders of sex development (DSD), ranging from sex reversal to severe hypospadias in 46,XY patients and premature ovarian failure (POF) in 46,XX patients. Previous reports have identified four families with a history of both 46,XY DSD and 46,XX POF carrying segregating NR5A1 sequence mutations. Recently, three 46,XY DSD sporadic cases with NR5A1 microdeletions have been reported. Here, we identify the first NR5A1 microdeletion transmitted in a pedigree with both 46,XY DSD and 46,XX POF. A 46,XY individual with DSD due to gonadal dysgenesis was born to a young mother who developed POF. Array CGH analysis revealed a maternally inherited 0.23 Mb microdeletion of chromosome 9q33.3, including the NR5A1 gene. Based on this finding, we screened patients with unexplained 46,XY DSD (n = 11), proximal hypospadias (n = 21) and 46,XX POF (n = 36) for possible NR5A1 copy-number variations (CNVs) via multiplex ligation-dependent probe amplification (MLPA), but did not identify any additional CNVs involving NR5A1. These data suggest that NR5A1 CNVs are an infrequent cause of these disorders but that array CGH and MLPA are useful genomic screening tools to uncover the genetic basis of such unexplained cases. This case is the first report of a familial NR5A1 CNV transmitting in a pedigree, causing both the male and female phenotypes associated with NR5A1 mutations, and the first report of a NR5A1 CNV associated with POF.