Gender identity outcome in female-raised 46,XY persons with penile agenesis, cloacal exstrophy of the bladder, or penile ablation

This review addresses the long-term gender outcome of gender assignment of persons with intersexuality and related conditions. The gender assignment to female of 46,XY newborns with severe genital abnormalities despite a presumably normal-male prenatal sex-hormone milieu is highly controversial because of variations in assumptions about the role of biological factors in gender identity formation. This article presents a literature review of gender outcome in three pertinent conditions (penile agenesis, cloacal exstrophy of the bladder, and penile ablation) in infancy or early childhood. The findings clearly indicate an increased risk of later patient-initiated gender re-assignment to male after female assignment in infancy or early childhood, but are nevertheless incompatible with the notion of a full determination of core gender identity by prenatal androgens.

The OEIS complex (omphalocele-exstrophy-imperforate anus-spinal defects): recurrence in sibs

The OEIS complex comprises a combination of defects including omphalocele, exstrophy of the cloaca, imperforate anus, and spinal defects. It may represent the most severe manifestation of a spectrum of birth defects, the exstrophy-epispadias sequence. The OEIS complex affects 1 in 200,000 to 400,000 pregnancies and is of unknown cause. The purpose of the current report is to document the occurrence of OEIS in sibs from separate pregnancies and suggest that some cases may have a genetic basis.

The inheritance of the exstrophy-epispadias complex

The inheritance pattern of the exstrophy-epispadias complex was investigated by a combined literature review and a survey of the personal experience of pediatric urologists in North and South America, and Europe. Bladder exstrophy recurred in only 9 of approximately 2,500 families (1 in 275) with bladder exstrophy or complete epispadias. The recurrence of the exstrophy-epispadias complex in offspring of parents with bladder exstrophy or complete epispadias has never been described previously. We identified 215 offspring produced by parents with bladder exstrophy or epispadias, and bladder exstrophy was inherited in 3 of the offspring (1 in 70 live births). The recurrence of bladder exstrophy in offspring of parents with the exstrophy-epispadias complex is greater than previously assumed.

DeltaNp63 plays an anti-apoptotic role in ventral bladder development

The bladder, the largest smooth-muscle organ in the human body, is responsible for urine storage and micturition. P63, a homolog of the p53 tumor-suppressor gene, is essential for the development of all stratified epithelia, including the bladder urothelium. The N-terminal truncated isoform of p63, DeltaNp63, is known to have anti-apoptotic characteristics. We have established that DeltaNp63 is not only the predominant isoform expressed throughout the bladder, but is also preferentially expressed in the ventral bladder urothelium during early development. We observed a host of ventral defects in p63-/- embryos, including the absence of the abdominal and ventral bladder walls. This number of ventral defects is identical to bladder exstrophy, a congenital anomaly exhibited in human neonates. In the absence of p63, the ventral urothelium was neither committed nor differentiated, whereas the dorsal urothelium was both committed and differentiated. Furthermore, in p63-/- bladders, apoptosis in the ventral urothelium was significantly increased. This was accompanied by the upregulation of mitochondrial apoptotic mediators Bax and Apaf1, and concurrent upregulation of p53. Overexpression of DeltaNp63gamma and DeltaNp63beta in p63-/- bladder primary cell cultures resulted in a rescue, evidenced by significantly reduced expressions of Bax and Apaf1. We conclude that DeltaNp63 plays a crucial anti-apoptotic role in normal bladder development.

Clinical and molecular characterization of the bladder exstrophy-epispadias complex: analysis of 232 families

OBJECTIVE

To identify genetic and nongenetic factors contributing to the risk of bladder exstrophy-epispadias complex (BEEC).

PATIENTS AND METHODS

In all, 285 families with BEEC were invited to participate in the study, and 232 of them were recruited. Epidemiological information was obtained from 151 of the consenting families, with a detailed clinical genetic examination of 94 probands. In all, 440 DNA samples were collected from 163 families for molecular analysis.

RESULTS

Most of the cases were sporadic and had no family history of BEEC. Among patients, 95% were Caucasian, and males were more common in both the epispadias group (M/F, 2.2, 29 patients) and the classic bladder-exstrophy group (M/F 1.8, 164), but in the cloacal exstrophy group the sex ratio was close to unity (1.1, 15). There was a statistically significant association with advanced parental age (P < 0.001). Birth weight, gestational age and maternal reproductive history did not appear to be significantly different from those in the general population. Information on exposures to tobacco, alcohol and drugs was collected but none appeared to act as a risk factor. Karyotype analysis on 37 cases detected two chromosomal abnormalities, i.e. 46XY t(8;9)(p11.2; q13) and 47XYY. Molecular analysis of the HLXB9 gene, which causes Currarino syndrome, did not detect mutations in the blood or bladder DNA of 10 patients with bladder or cloacal exstrophy.

CONCLUSIONS

BEEC most commonly occurs as an isolated sporadic birth defect with a recurrence risk of << 1%. There was no evidence of a single-gene effect or common environmental factor in this study population. In addition to race and advanced parental age, birth order may be a risk factor for BEEC. We suggest somatic mutations in a gene(s) within the pathway regulating bladder development may be the cause of BEEC.

Cloacal exstrophy in an infant with 9q34.1-qter deletion resulting from a de novo unbalanced translocation between chromosome 9q and Yq

Cloacal exstrophy is a rare malformation, belonging to a spectrum of birth defects, which, in order of severity, includes phallic separation with epispadias, pubic diastasis, bladder exstrophy, and cloacal exstrophy. This malformation overlaps the OEIS complex (O = omphalocele, E = bladder exstrophy, I = imperforate anus, S = spinal defects). The etiology of cloacal exstrophy is unknown to date. It may result from either a single defect of early blastogenesis or a defect of mesodermal migration during the primitive streak period. We report an infant with cloacal exstrophy, exomphalos, right kidney agenesis, ambiguous external genitalia, and axial hypotonia. The karyotype showed a de novo unbalanced translocation between the long arm of chromosome 9 and the long arm of chromosome Y resulting in a 9q34.1-qter deletion. Reviewing the literature, we did not find any observation of cloacal exstrophy associated with a structural chromosomal abnormality. The steroidogenic factor 1 (SF1) gene, included in the deleted region, was a good candidate gene but no pathogenic mutation was found by direct sequencing. We hypothesize that another gene, expressed early in embryogenesis and responsible for cloacal exstrophy, is present in the 9q34.1-qter region.

Epidemiological survey of 214 families with bladder exstrophy-epispadias complex

PURPOSE

We sought to identify causative nongenetic and genetic risk factors for the bladder exstrophy-epispadias complex.

MATERIALS AND METHODS

A total of 237 families with the bladder exstrophy-epispadias complex were invited to participate in the study, and information was obtained from 214 families, mainly from European countries.

RESULTS

Two families showed familial occurrence. Male predominance was found among all subgroups comprising epispadias, classic bladder exstrophy and cloacal exstrophy, with male-to-female ratios of 1.4:1, 2.8:1 and 2.0:1, respectively (p = 0.001). No association with parental age, maternal reproductive history or periconceptional maternal exposure to alcohol, drugs, chemical noxae, radiation or infections was found. However, periconceptional maternal exposure to smoking was significantly more common in patients with cloacal exstrophy than in the combined group of patients with epispadias/classic bladder exstrophy (p = 0.009). Only 16.8% of mothers followed the current recommendations of periconceptional folic acid supplementation, and 17.6% had started supplementation before 10 weeks of gestation. Interestingly, in the latter group mothers of patients with cloacal exstrophy were more compliant with folic acid supplementation than were mothers of the combined group of patients with epispadias/classic bladder exstrophy (p = 0.037). Furthermore, mothers of children with cloacal exstrophy knew significantly more often prenatally that their child would have a congenital malformation than did mothers of children with epispadias/classic bladder exstrophy (p <0.0001).

CONCLUSIONS

Our study corroborates the hypothesis that epispadias, classic bladder exstrophy and cloacal exstrophy are causally related, representing a spectrum of the same developmental defect, with a small risk of recurrence within families. Embryonic exposure to maternal smoking appears to enforce the severity, whereas periconceptional folic acid supplementation does not seem to alleviate it. There is a disproportional prenatal ultrasound detection rate between severe and mild phenotypes, possibly due to the neglect of imaging of full bladders with a focus on neural tube defects.

Psychosexual development in genetic males assigned female: the cloacal exstrophy experience

Genetic males who have cloacal exstrophy, a rare, severe pelvic field defect that leads to aphallia, traditionally have been socially, legally, and surgically sex-assigned female at birth and reared female, despite a male karyotype and a typical male prenatal hormonal milieu. Psychosexual development in such children previously has been unknown. Studies of 29 children revealed that despite the absence of the typical postnatal and pubertal androgen surges and the presence of female genitalia, all female-assigned subjects displayed a marked male-typical shift in psychosocial and psychosexual development. Nearly half of them have declared themselves male. Psychosexual development, including gender identity, in genetic and hormonal male neonates seems to be influenced heavily by prenatal androgen exposure. The clinical practice of surgical sex assignment at birth requires re-evaluation.

A family study of bladder exstrophy

The families of 102 index patients with bladder exstrophy treated at The Hospital for Sick Children, Great Ormond Street were studied in an attempt to arrive at an empirical risk of recurrence for sibs. Of the 102 patients, 89 had complete exstrophy, eight had partial exstrophy (variant), and five had exstrophy of the cloaca. In all they had 162 sibs, none of whom had bladder exstrophy. The risk to sibs, in this study and from reports by surgeons of sib pairs in their consecutive series, is low and probably less than 1%. There is a suggestion of an increase in central nervous system malformation in sibs as well as in the index patients.

Seven new cases of familial isolated bladder exstrophy and epispadias complex (BEEC) and review of the literature

Clustering of the bladder exstrophy and epispadias complex (BEEC) has been described in 29 families. To explore the genetic contribution we located new families through the German and Austrian Bladder Exstrophy Support Group and the Association for the Bladder Exstrophy Community (predominantly US and Canada). We report six new families with two occurrences of BEEC, one family where the proband is the product of a consanguineous union, and four discordant twin pairs. In conjunction with the published clinical and epidemiological reports this collection suggests that there is a significant genetic predisposition for susceptibility to the BEEC. It also highlights the importance of self-referral groups for recruiting families for multicenter collaborative research efforts to identify susceptibility loci.

Four cases of bladder exstrophy in two families

Bladder exstrophy is a rare congenital anomaly, caused by abnormal development of the cloacal membrane. To our knowledge, 18 familial patients with this malformation have been described. Two sets of familial cases with bladder exstrophy are reported here: two cousins and a mother and son and the published reports of the 18 familial cases among 682 index patients with bladder exstrophy are reviewed. Ultrasonography is advocated as the investigation of choice for early prenatal diagnosis.

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.

Psychopathology, Psychosocial, Gender and Cognitive Outcomes in Patients With Cloacal Exstrophy

PURPOSE

Psychological functioning, as reflected in psychopathology, psychosocial functioning, gender identity, gender role and cognitive abilities, was examined in a sample of patients with cloacal exstrophy.

MATERIALS AND METHODS

Nine participants 11 to 37 years old completed the evaluation. Standardized measures were used and participant responses were compared to the norms of the various instruments. Gender reassigned participants with cloacal exstrophy were compared with nonassigned participants with cloacal exstrophy. Mean differences between the 2 groups were calculated using the t test.

RESULTS

Overall the participants with cloacal exstrophy reported good psychological functioning. Significant differences between reassigned and nonassigned participants were found in the area of depression. All participants had a stable gender identity. XY females showed more male-typical gender roles. There were no significant group differences on cognitive assessments. Reassigned and nonassigned participants did not differ in IQ.

CONCLUSIONS

Although being born with cloacal exstrophy puts patients at risk for psychopathology and psychosocial problems, it does not necessarily mean that these problems will develop. With the appropriate support these patients can have remarkably well adjusted lives.

Prospective management of exstrophy of the cloaca and myelocystocele following prenatal ultrasound recognition of neural tube defects in identical twins

We describe identical twins concordant for exstrophy of the cloaca and myelocystocele. Their management and subsequent course was strongly influenced by prenatal ultrasound recognition of neural tube defects in both twins and severe renal dysplasia in one of the fetuses. The genetic aspects of this case are consistent with existing causal theories of exstrophy of the cloaca.

Insertion/deletion polymorphisms in the ΔNp63 promoter are a risk factor for bladder exstrophy epispadias complex

Bladder exstrophy epispadias complex (BEEC) is a severe congenital anomaly; however, the genetic and molecular mechanisms underlying the formation of BEEC remain unclear. TP63, a member of TP53 tumor suppressor gene family, is expressed in bladder urothelium and skin over the external genitalia during mammalian development. It plays a role in bladder development. We have previously shown that p63^−/− mouse embryos developed a bladder exstrophy phenotype identical to human BEEC. We hypothesised that TP63 is involved in human BEEC pathogenesis. RNA was extracted from BEEC foreskin specimens and, as in mice, ΔNp63 was the predominant p63 isoform. ΔNp63 expression in the foreskin and bladder epithelium of BEEC patients was reduced. DNA was sequenced from 163 BEEC patients and 285 ethnicity-matched controls. No exon mutations were detected. Sequencing of the ΔNp63 promoter showed 7 single nucleotide polymorphisms and 4 insertion/deletion (indel) polymorphisms. Indel polymorphisms were associated with an increased risk of BEEC. Significantly the sites of indel polymorphisms differed between Caucasian and non-Caucasian populations. A 12-base-pair deletion was associated with an increased risk with only Caucasian patients (p = 0.0052 Odds Ratio (OR) = 18.33), whereas a 4-base-pair insertion was only associated with non-Caucasian patients (p = 0.0259 OR = 4.583). We found a consistent and statistically significant reduction in transcriptional efficiencies of the promoter sequences containing indel polymorphisms in luciferase assays. These findings suggest that indel polymorphisms of the ΔNp63 promoter lead to a reduction in p63 expression, which could lead to BEEC.

Bladder exstrophy epispadias complex is a severe congenital abnormality. The affected babies' bladders are born open, leaking urine constantly. Treatment involves multiple major reconstructive surgeries and the need for lifelong care for the complications of the disease. Although a number of studies have suggested a genetic cause of the disease, the genetic and molecular mechanism underlying the formation of BEEC remains unknown. One gene, TP63, plays a crucial role in the early bladder development. Two different genetic promoters of TP63 produce different forms of the protein with opposing properties. We have shown mice lacking p63 displayed a deformity complex identical to human BEEC. There are no genetic mutations in the p63 protein in BEEC, so genetic variants in the promoter could alter protein expression. Our hypothesis was that loss of p63 expression due to sequence polymorphisms in a promoter is a risk factor for BEEC. We found promoter sequence variants that were statistically associated with the disease and the sequence variant location varied between Caucasian and non-Caucasian patients. This is particularly important as Caucasian populations have a higher risk of BEEC. These findings provide an explanation of BECC and a base for further study of TP63 related genes in this disease.

Syndromes and Disorders Associated with Omphalocele (II): OEIS Complex and Pentalogy Of Cantrell

Omphalocele-exstrophy-imperforate anus-spinal defects (OEIS) complex is characterized by a combination of omphalocele, exstrophy of the bladder, an imperforate anus, and spinal defects. Pentalogy of Cantrell is characterized by a combination of a midline supraumbilical abdominal wall defect, a defect of the lower sternum, a defect of the diaphragmatic pericardium, a deficiency of the anterior diaphragm, and congenital cardiac anomalies. This article provides a comprehensive review of OEIS complex and pentalogy of Cantrell, including the pathogenesis, prenatal diagnosis, differential diagnosis, and associated malformations. Omphalocele is an important sonographic marker for OEIS complex and pentalogy of Cantrell. Prenatal detection of an abdominal wall defect associated with multiple midline defects should alert one to the possibility of OEIS complex and pentalogy of Cantrell and prompt the genetic investigation and counseling of the disorders.

Genetische und molekularbiologische Aspekte des Blasenekstrophie-Epispadie-Komplexes (BEEK)

The bladder exstrophy and epispadias complex (BEEC) is an anterior midline defect with variable expression involving the infraumbilical abdominal wall including the pelvis, urinary tract, and external genitalia. The incidence varies with regard to ethnical background, sex, and phenotypic expression, and an incidence of 1:20,000 to 1:80,000 has been observed in the middle European population. No gene defect has been attributed to BEEC thus far and chromosomal aberrations or genetic syndromes associated with BEEC have only rarely been reported. According to epidemiological data, a complex genetic as well as a multifactorial mode of inheritance could underlie BEEC. However, no single teratogenic agent or environmental factor has been identified, which could play a dominant role in the expression of the BEEC.A risk of recurrence of 0.5-3% has been described in families with one affected subject. These values correspond to an increased recurrence risk estimated to be as high as 200- to 800-fold when compared to the common population. Due to the paucity of affected sib pairs and suitable multiplex families, conventional linkage analysis to identify candidate genes causally related with BEEC appears to be unfeasible. Large association studies and consecutive linkage disequilibrium mapping should therefore lead to the identification of candidate genes. Also new methods including matrix-based comparative genomic hybridization (CGH) are promising and have successfully been used in the past (e.g., CHARGE association). Moreover, the low incidence of the BEEC requires close cooperation between clinicians in the operative and nonoperative specialties as well as geneticists for successful gene search.

A reciprocal translocation 46,XY,t(8;9)(p11.2;q13) in a bladder exstrophy patient disrupts CNTNAP3 and presents evidence of a pericentromeric duplication on chromosome 9

A patient with sporadic bladder exstrophy and de novo apparently balanced chromosomal translocation 46,XY,t(8;9)(p11.2;q13) was analyzed by fluorescence in situ hybridization (FISH) and molecular methods. We were able to map both translocation breakpoints to single genomic clones. The chromosome 8p11.2 breakpoint was mapped to BAC clone RP4-547J18, predicted to contain several hypothetical genes. Characterization of the chromosome 9q13 breakpoint indicated a disruption in the 5' region of CNTNAP3 within BAC RP11-292B8. This observation suggests possible involvement of CNTNAP3 in the etiology of bladder exstrophy. Additionally, FISH analysis identified several genomic copies of CNTNAP3 on both sides of the chromosome 9 centromere flanking the polymorphic heterochromatin. Northern blot analysis of lymphoblast and bladder RNA confirmed CNTNAP3 transcripts in these tissues and did not show abnormal CNTNAP3 expression in the proband and two unrelated patients with bladder exstrophy. The identification of multiple copies of three BAC clones in the proband, his parents, and unrelated controls suggests that duplications of CNTNAP3 and the surrounding genomic region have occurred as a result of repeated events of unequal crossing over and pericentric inversions during chromosome 9 evolution.

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.

New insights into the pathogenesis of bladder exstrophy-epispadias complex

Bladder exstrophy-epispadias complex (BEEC) is a complex and debilitating congenital disease. Familial and twin studies suggest a possible genetic component in BEEC pathogenesis. Bladder mesenchyme (detrusor) development requires induction by a signal from bladder urothelium, and we and others have shown the Shh-Gli-Bmp4 signalling pathway is likely to be involved. P63 is a master regulator in epithelial stratification and is expressed in urothelium. We have shown that p63 knock-out mice undergo excessive urothelial apoptosis. Failure of mesenchymal induction by epithelium leads to BEEC. We further demonstrated that insertion/deletion (in/del) polymorphisms (1 base pair (bp) ins and 4 bp ins., and 12 bp del) in the ΔNP63 promoter reduce transcriptional efficiency, and are associated with a statistically significant increase in the risk of BEEC in humans. Furthermore, a Genome-Wide Expression Profiling (GWEP) study suggests possible involvement of PERP in human BEEC. Intriguingly, PERP is a direct target of p63 during development, and is also involved in epithelial stratification. PERP co-localizes with desmosome, and both PERP and desmosome are essential for maintaining tissue integrity by cellular adhesion and epithelial stratification. A recent study showed that PERP and desmosome expression levels are abnormal in human BEEC patients. This review describes the role of the P63 > PERP > desmosome pathway in the development of human bladder during embryogenesis. We hypothesize that disruption of this pathway may increase the risk of BEEC.

Another case of autosomal dominant exstrophy of the bladder

OBJECTIVE

Exstrophy of the bladder is a rare malformation due to an anterior midline defect. Most cases of this condition with variable expression occur sporadically, but there are some cases indicative of a strong genetic component apart from environmental factors. This is a report about another rare mother-child pair with bladder exstrophy.

METHODS

We present the clinical data of a familial case of bladder exstrophy with an affected mother and her equally affected male fetus.

RESULTS

Prenatal diagnosis of bladder exstrophy in the fetus was assessed by ultrasound at the 19th gestational week and was confirmed after termination of pregnancy at the 21st gestational week.

CONCLUSION

The present case may be additional evidence for an autosomal dominant inherited variant of this malformation complex with implication for counselling of affected patients.

Bladder exstrophy–epispadias complex: Investigation of suppressor of variegation, enhancer of zeste and Trithorax (SET) as a candidate gene in a large cohort of patients

OBJECTIVE

The bladder exstrophy-epispadias complex (BEEC) describes a rare anterior midline defect with variable expression involving the infra-umbilical abdominal wall, including the pelvis, urinary tract and external genitalia. It is assumed that the underlying cause of BEEC is a multifactorial mode of inheritance; however, its aetiology remains unknown. Only a few BEEC patients with distinctive cytogenetic features such as numeric or structural chromosomal abnormalities have been reported. The observation of translocations concerning the region of chromosome 9q32-q34.1 in two patients implies that this region bears a candidate gene which, during early blastogenesis, governs the development of this primary field. In this context, we considered the suppressor of variegation, enhancer of zeste and Trithorax (SET) gene, located at chromosome 9q34, to be a good candidate, as the protein encoded is involved in the regulation of cell proliferation and differentiation. Moreover, SET expression was detected in embryonic kidney.

MATERIAL AND METHODS

A total of 33 patients affected with BEEC were analysed for mutations in the SET gene.

RESULTS

SET analysis did not reveal either a mutation or the presence of four single-nucleotide polymorphisms (dbSNP124) already described in the database.

CONCLUSIONS

The data obtained in this study most likely exclude the SET gene as a possible genetic cause of BEEC. Hence, other genes in this region may contribute to the development of this midline defect.

Phenotypic and functional characterization of in vivo tissue engineered smooth muscle from normal and pathological bladders

PURPOSE

The engineering of bladder tissue involves obtaining a biopsy from a host, expanding the cells, seeding them onto a matrix and implanting the cell-matrix composite back into the host. Clinically, cells used for these techniques may be harvested from abnormal bladders. It is not known whether abnormal bladder cells may be engineered into functionally normal tissue. We investigated the phenotypic and functional characteristics of tissue engineered bladder smooth muscle derived from patients with functionally normal bladders and functionally abnormal exstrophic and neuropathic bladders.

MATERIALS AND METHODS

Human smooth muscle cells derived from functionally normal bladders, exstrophic bladders and neurogenic bladders were grown, expanded and seeded onto polymer scaffolds. Sixteen cell seeded scaffolds were analyzed in vitro and 40 cell seeded scaffolds were implanted in athymic mice. The tissue engineered constructs were retrieved and analyzed at 2 weeks and 2 months. The scaffolds were evaluated immunocytochemically, histologically, with organ bath studies and with Western blot analyses.

RESULTS

Human bladder cells showed similar expression of smooth muscle marker proteins (alpha-actin and myosin) in vitro and after 2 months in vivo, regardless of their origin. All scaffolds showed similar muscle formation in vivo. The cell seeded scaffolds demonstrated the typical "contraction-relaxation" response to supramaximal electrical field and carbachol stimulation. There were no statistical differences among the experimental groups (normal, exstrophic, neurogenic).

CONCLUSIONS

Tissue engineered muscle from normal and diseased bladders retain their phenotype in vitro and after implantation in vivo. The cells exhibited the same degree of contractility to electrical and chemical stimulation regardless of their origin. These results suggest that there are no phenotypic or functional differences between muscle cells obtained from urodynamically normal or pathological bladders, and that bladder muscle cells, regardless of their origin, may have the potential to be engineered into normal bladder tissues.

Bladder exstrophy and epispadias complex in sibling: case report and review of literature

The bladder exstrophy and classic epispadias represent a spectrum of congenital anomalies with different degrees of anterior midline defect. Although the anomaly usually occurs sporadically there are some cases indicative of a strong genetic component. We present the clinical data of two siblings with bladder exstrophy and epispadias complex (BEEC), who were the product of consanguineous union. All previous reports of familial BEEC in the literature have been reviewed.