Karin Hirsch

Genome-wide Association Study and Meta-Analysis Identify ISL1 as Genome-wide Significant Susceptibility Gene for Bladder Exstrophy

The bladder exstrophy-epispadias complex (BEEC) represents the severe end of the uro-rectal malformation spectrum, and is thought to result from aberrant embryonic morphogenesis of the cloacal membrane and the urorectal septum. The most common form of BEEC is isolated classic bladder exstrophy (CBE). To identify susceptibility loci for CBE, we performed a genome-wide association study (GWAS) of 110 CBE patients and 1,177 controls of European origin. Here, an association was found with a region of approximately 220kb on chromosome 5q11.1. This region harbors the ISL1 (ISL LIM homeobox 1) gene. Multiple markers in this region showed evidence for association with CBE, including 84 markers with genome-wide significance. We then performed a meta-analysis using data from a previous GWAS by our group of 98 CBE patients and 526 controls of European origin. This meta-analysis also implicated the 5q11.1 locus in CBE risk. A total of 138 markers at this locus reached genome-wide significance in the meta-analysis, and the most significant marker (rs9291768) achieved a P value of 2.13 × 10−12. No other locus in the meta-analysis achieved genome-wide significance. We then performed murine expression analyses to follow up this finding. Here, Isl1 expression was detected in the genital region within the critical time frame for human CBE development. Genital regions with Isl1 expression included the peri-cloacal mesenchyme and the urorectal septum. The present study identified the first genome-wide significant locus for CBE at chromosomal region 5q11.1, and provides strong evidence for the hypothesis that ISL1 is the responsible candidate gene in this region.

Genome-wide association study and mouse expression data identify a highly conserved 32 kb intergenic region between WNT3 and WNT9b as possible susceptibility locus for isolated classic exstrophy of the bladder

Bladder exstrophy-epispadias complex (BEEC), the severe end of the urorectal malformation spectrum, has a profound impact on continence as well as sexual and renal functions. It is widely accepted that for the majority of cases the genetic basis appears to be multifactorial. Here, we report the first study which utilizes genome-wide association methods to analyze a cohort comprising patients presenting the most common BEEC form, classic bladder exstrophy (CBE), to identify common variation associated with risk for isolated CBE. We employed discovery and follow-up samples comprising 218 cases/865 controls and 78 trios in total, all of European descent. Our discovery sample identified a marker near SALL1, showing genome-wide significant association with CBE. However, analyses performed on follow-up samples did not add further support to these findings. We were also able to identify an association with CBE across our study samples (discovery: P = 8.88 × 10(-5); follow-up: P = 0.0025; combined: 1.09 × 10(-6)) in a highly conserved 32 kb intergenic region containing regulatory elements between WNT3 and WNT9B. Subsequent analyses in mice revealed expression for both genes in the genital region during stages relevant to the development of CBE in humans. Unfortunately, we were not able to replicate the suggestive signal for WNT3 and WNT9B in a sample that was enriched for non-CBE BEEC cases (P = 0.51). Our suggestive findings support the hypothesis that larger samples are warranted to identify association of common variation with CBE.

Assisted Reproductive Techniques and Risk of Exstrophy-Epispadias Complex: A German Case-Control Study

PURPOSE We assessed the risk of exstrophy-epispadias complex in children conceived by in vitro fertilization or intracytoplasmic sperm injection. MATERIALS AND METHODS Data from the German Network for Congenital Uro-REctal malformations were compared to nationwide data from the German In Vitro Fertilization Register and the German Federal Statistical Office. Odds ratios (95% CI) were determined to quantify associations using logistic regression. RESULTS A total of 123 patients with exstrophy-epispadias complex born in Germany between 1997 and 2011 were recruited through participating departments of pediatric urology and pediatric surgery throughout the country as well as the German self-help organizations Blasenekstrophie/Epispadie e.V. and Kloakenekstrophie. All German live births (10,069,986) between 1997 and 2010 comprised the controls. Overall, 12 subjects (10%) and 129,982 controls (1%) were conceived by in vitro fertilization or intracytoplasmic sperm injection. Conception by assisted reproductive technique was associated with a more than eightfold increased risk of exstrophy-epispadias complex compared to spontaneous conception (OR 8.3, 95% CI 4.6-15.0, p <0.001). Separate analyses showed a significantly increased risk of exstrophy-epispadias complex in children conceived by in vitro fertilization (OR 14.0, 95% CI 6.5-30.0, p <0.0001) or intracytoplasmic sperm injection (OR 5.3, 95% CI 2.2-12.9, p <0.0001). CONCLUSIONS This study provides evidence that assisted reproductive techniques such as in vitro fertilization and intracytoplasmic sperm injection are associated with a markedly increased risk of having a child born with exstrophy-epispadias complex. However, it remains unclear whether this finding may be due to assisted reproduction per se and/or underlying infertility/subfertility etiology or parent characteristics.

Sexual Function and Quality of Life in Adult Male Individuals with Exstrophy-Epispadias Complex—a Survey of the German CURE-Network

OBJECTIVE To investigate sexual function and quality of life (QoL) in adult male individuals with exstrophy-epispadias complex (EEC). Data from the German Network for Congenital Urorectal Malformations (CURE-Net) were used. PATIENTS AND METHODS Fifty-one male participants (≥18 years) recruited by CURE-Net between 2009 and 2012 were re-contacted per mail and asked to fill out 4 questionnaires including International Index of Erectile Function (IIEF-5), Cologne Assessment of Erectile Dysfunction (KEED), the Short-Form 36 (SF-36), and one self-designed questionnaire about their medical history, current health status, and sexual experience. The SF-36 results were compared with general German population. RESULTS Nineteen male participants (37%) completed all questionnaires (median age 26 years, 84% classical bladder exstrophy). The majority (68%) was reconstructed in a staged or single-staged approach; further 32% had a primary urinary diversion. Seventy-four percent of the participants reported a certain degree of urinary incontinence. Mean IIEF-15 results showed mild to moderate or moderate impairment in all domains. The SF-36 results revealed no difference in the German population. Subgroup analysis showed statistically significant lower results in certain SF-36 domains with regard to incontinence, dissatisfaction with genital appearance, and antihypertensive drug intake. CONCLUSION Although there is no difference in overall QoL comparing male individuals with EEC to the general German population, incontinence, dissatisfaction with genital appearance, and taking antihypertensive medication seem to have a considerable impact on QoL. Furthermore, mild to moderate erectile dysfunction and moderate intercourse satisfaction were confirmed, suggesting the need for further improvement in care for adult male individuals with EEC.

Umbilical rotation: A new technique for the cutaneous fixation of continent catheterizable vesicostomies

PURPOSE For cutaneous fixation of the continent catheterizable vesicostomy we present a new technique, in which the umbilicus is rotated caudally by 180° and the catheterizable channel is sutured to the umbilical cone. This procedure reduces the distance between the stoma entrance and the bladder. MATERIALS AND METHODS Between 2001 and 2008, 67 patients underwent construction of a continent catheterizable vesicostomy. In 82% (n = 55), this was an appendicovesicostomy according to the Mitrofanoff principle. For 21 of these patients, later in the series (2005 onwards), the procedure involved rotation of the umbilicus. We evaluated cosmetic outcome and channel-related complication rates and compared the results between the two groups, with and without umbilical rotation. RESULTS The overall complication rate was 22.4% (n = 15); stoma stenosis occurred in eight cases. In the majority of cases with complications, endoscopic treatment was sufficient. The complication rate was significantly lower in the group with umbilical rotation compared to the other group (14.3% vs 26.1%, P < 0.02). CONCLUSIONS Umbilical rotation always enables cutaneous implantation of the vesicostomy in the umbilical pit and is a safe and straightforward procedure.

“Strawberry wees forever?”: questions

One Thursday night we received an excited phone call from a urologist in private practice asking us to have a look at the strange “strawberry yoghurt-like” urine of a 13-year-old girl. We were curious to see both urine and girl the same night and met a fit and healthy-looking 13-year-old Bavarian girl with a 6-week history of intermittent flank pain and thick, “strawberry yoghurt-like” urine (Fig. 1). She had been discharged from an external hospital 4 weeks earlier with the diagnosis of nephritic proteinuria and microhematuria. There was no path-breaking past medical or family history, no signs of an infection or underlying trauma, and no foreign travel. Physical examination was normal, with no edema, no fever, and a normotensive blood pressure. Her renal function was not impaired (creatinine 0.60 mg/dl). The analysis of her thick and cloudy pink urine revealed a gross, albumin-rich proteinuria (4,542 mg/m/dl) and a gross hematuria (3,500/μl, isomorphic) in combination with a significant amount of lipids with a high triglyceride (582 mg/dl) content, but no leucocytes. In contrast to nephrotic syndrome, serum triglyceride levels were low (51 mg/dl) and no hypoalbuminemia (40.2 g/l) was present. The results of all other laboratory tests, including a coagulation screen, were normal. Given our suspicion of the most likely underlying cause of this condition as well as the current well-being of our patient, we made an appointment for further assessment the following week. However, the girl had to be admitted to our hospital only 2 days later after she had passed a 1×2-cm large fibroid polyp with her urine. The intended diagnostic workflow was therefore abandoned. A clinical urological

“Strawberry wees forever?”: Answers

1. Chyluria, the loss of chyle via the urinary tract, is a rare condition among children. 2. Non-parasitic forms of childhood chyluria are predominantly observed in Western countries. 3. Consistent with chyle leakage from the upper urinary tract or bladder the T2-sequence of the magnetic resonance tomography (MRT)–urography showed a ventral hypointense chyluric layer on top of the hyperintense urine. We then performed a cystoscopy, the leading diagnostic intervention in childhood chyluria, in order to locate a fistula between the lymphatic and urinary system. Discussion