[Lower urinary tract obstruction (LUTO)--clinical picture, prenatal diagnostics and therapeutic options]. / Lower Urinary Tract Obstruction (LUTO)--Krankheitsbild, pränatale Diagnostik und Therapiemöglichkeiten.

The aetiology of urinary tract obstructions (LUTO) is heterogeneous. The most common entities are isolated posterior urethral valves or urethral atresia in male foetuses. In female foetuses LUTO is frequently a part of complex malformations. The natural history of LUTO is characterised by high morbidity and mortality due to the development of severe pulmonary hypoplasia caused by oligo- or anhydramnios affecting the cannalicular phase (16-24 weeks of gestation) of pulmonary development. The degree of renal damage is variable and ranges from mild renal impairment in infancy to end-stage renal insufficiency, necessitating dialysis and transplantation. Foetal interventions in order to bypass the obstruction are biologically plausible and technically feasible. Vesico-amniotic shunting as well as (currently less frequent) foetoscopic cystoscopy and laser ablation of posterior urethral valves are minimally invasive treatment options. Previous reports indicate that prenatal therapy is suitable to reduce perinatal mortality but does not improve postnatal renal function. Selection of foetuses who may profit from prenatal intervention is aggravated by the lack of reliable prognostic criteria for the prediction of postnatal renal function in both ultrasound and foetal urine analysis. Furthermore, there is no randomised trial available at the time of writing. Because of a relevant complication rate and still no clear evidence for foetal benefit, interventions should be performed in specialised centres. Further studies are necessary to improve case selection of affected foetuses and to evaluate the impact of interventions in earlier gestational weeks. The data from the PLUTO trial (percutaneous shunting in lower urinary tract obstruction) conducted by the University of Birmingham may help to answer these questions. In the meantime selection of foetuses for prenatal intervention puts high requirements on interdisciplinary counselling in every case. A general treatment algorithm for foetal therapy is not available at the moment.

Hypomorphic mutations in meckelin (MKS3/TMEM67) cause nephronophthisis with liver fibrosis (NPHP11).

BACKGROUND: Nephronophthisis (NPHP), a rare recessive cystic kidney disease, is the most frequent genetic cause of chronic renal failure in children and young adults. Mutations in nine genes (NPHP1-9) have been identified. NPHP can be associated with retinal degeneration (Senior-Løken syndrome), brainstem and cerebellar anomalies (Joubert syndrome), or liver fibrosis. METHODS: To identify a causative gene for the subset of patients with associated liver fibrosis, the authors performed a genome wide linkage search in a consanguineous family with three affected patients using 50K SNP microarrays and homozygosity mapping. RESULTS: The authors obtained a significant maximum parametric LOD (logarithm of odds) score of Z(max) = 3.72 on chromosome 8q22 and identified a homozygous missense mutation in the gene MKS3/TMEM67. When examining a worldwide cohort of 62 independent patients with NPHP and associated liver fibrosis we identified altogether four novel mutations (p.W290L, p.C615R, p.G821S, and p.G821R) in five of them. Mutations of MKS3/TMEM67, found recently in Meckel-Gruber syndrome (MKS) type 3 and Joubert syndrome (JBTS) type 6, are predominantly truncating mutations. In contrast, the mutations detected here in patients with NPHP and associated liver fibrosis are exclusively missense mutations. This suggests that they may represent hypomorphic alleles, leading to a milder phenotype compared with the more severe MKS or JBTS phenotype. Additionally, mutation analysis for MKS3/TMEM67 in 120 patients with JBTS yielded seven different (four novel) mutations in five patients, four of whom also presented with congenital liver fibrosis. CONCLUSIONS: Hypomorphic MKS3/TMEM67 mutations cause NPHP with liver fibrosis (NPHP11). This is the first report of MKS3 mutations in patients with no vermian agenesis and without neurological signs. Thus NPHP, JBTS, and MKS represent allelic disorders.

Infantile hypophosphatasia due to a new compound heterozygous TNSALP mutation - functional evidence for a hydrophobic side-chain?

BACKGROUND: Infantile hypophosphatasia (IH) is an inherited disorder characterized by defective bone mineralization and a deficiency of alkaline phosphatase activity. OBJECTIVE/DESIGN: The aim of the study was to evaluate a new compound heterozygous TNSALP mutation for its residual enzyme activity and localization of the comprised amino acid residues in a 3D-modeling. PATIENT: We report on a 4-week old girl with craniotabes, severe defects of ossification, and failure to thrive. Typical clinical features as low serum alkaline phosphatase, high serum calcium concentration, increased urinary calcium excretion, and nephrocalcinosis were observed. Vitamin D was withdrawn and the patient was started on calcitonin and hydrochlorothiazide. Nonetheless, the girl died at the age of 5 months from respiratory failure. RESULTS: Sequence analysis of the patient's TNSALP gene revealed two heterozygous mutations [c.653T>C (I201T), c.1171C>T (R374C)]. Transfection studies of the unique I201T variant in COS-7 cells yielded a mutant TNSALP protein with only a residual enzyme activity (3.7%) compared with wild-type, whereas the R374C variant was previously shown to reduce normal activity to 10.3%. 3D-modeling of the mutated enzyme showed that I201T resides in a region that does not belong to any known functional site. CONCLUSION: We note that I201, which has been conserved during evolution, is buried in a hydrophobic pocket and, therefore, the I>T-change should affect its functional properties. Residue R374C is located in the interface between monomers and it has been previously suggested that this mutation affects dimerization. These findings explain the patient's clinical picture and severe course.

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.

Dysphagia due to triple A syndrome: successful treatment of achalasia by balloon dilatation.

UNLABELLED: Triple A syndrome is a rare autosomal recessive inherited disorder which is characterized by alacrima, adrenal insufficiency, and achalasia. We report on a 14-year old girl with dysphagia, regurgitation, and vomiting since 5 years. At the age of five years an Addison crisis was diagnosed and cortisone substitution was initiated. In addition, the patient had episodes of conjunctivitis. Severe esophagitis and candida infection were diagnosed by esophago-gastro-duodenoscopy and treated with omeprazole and fluconazole. The esophageal barium swallow was typical for achalasia. Medical treatment of achalasia with oral nifedipine resulted only in a partial and temporal improvement. But after seven balloon dilatations dysphagia and nocturnal coughing improved clearly and a remarkable gain of weight could be seen. Direct sequencing showed a homozygous nonsense mutation in exon 11 of the AAAS gene leading to truncation at position 342 of the 546 amino acid protein. CONCLUSION: Triple A syndrome has to be considered in patients with dysphagia. In our patient, the absence of tears since birth followed by adrenal insufficiency were early signs of the triple A syndrome. Balloon dilatation of the esophago-gastric junction is an effective treatment, which can avoid surgical interventions.

[Genetic and molecular biological aspects of the bladder exstrophy-epispadias complex (BEEC)]. / 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.

Genetic and molecular aspects of hypospadias.

Hypospadias, a midline fusion defect of the male ventral urethra, is a relatively common genital anomaly occurring in 0.3 - 7 of 1000 live male births. The anatomical location of the misplaced urethral meatus determines the severity of this anomaly with the severity increasing from distal to proximal. Glandular and penile hypospadias, the most common forms, often appear as an isolated anomaly and account for the majority of hypospadias, whereas about 20 % are classified as scrotal and perineal types. These latter forms frequently occur in association with other genital anomalies such as microphallus, bifid scrotum, penoscrotal transposition, and cryptorchidism, and may represent an intersex phenotype. Besides a higher incidence in consanguineous families and a suggested recessive inheritance, in other families a dominant transmission is likely. The recurrence risk in the next generation seems to be correlated with the severity of hypospadias. Only 30 % of severe hypospadias can be attributed to defects in the synthesis of testosterone or adrenal steroid hormones, receptor defects, syndrome-associated hypospadias, chromosomal anomalies, defects in other genetic factors, or exogenous forms. To identify the underlying causes of the remaining 70 % "idiopathic" hypospadias, familial and twin studies were performed. Familial studies can help identify gene loci and, subsequently, candidate genes by mutational analysis. Either linkage analysis in large families with many affected individuals suspicious for a monogenic trait or association studies in cases of a complex inheritance in many families with a few affected individuals can be performed. Microarrays and proteomics can help detect gene expression or protein differences. Furthermore, genetically modified animal models can be used to detect phylogenetically homologous genes in man. In addition to an optimal documentation and acquisition of blood and tissue samples this requires a close cooperation between clinicians in the operative and non-operative specialties as well as geneticists.

[High dose chemotherapy with thiotepa, carboplatin, VP16 and autologous stem cell transplantation in treatment of malignant brain tumors with poor prognosis. Results of a mono-center pilot study]. / Hochdosischemotherapie mit Thiotepa, Carboplatin, VP16 und autologer Stammzelltransplantation in der Behandlung von malignen Hirntumoren mit schlechter Prognose. Ergebnisse einer monozentrischen Pilotstudie.

More than half of the children and adolescents with malignant brain tumors will relapse following initial therapy. Irrespective of the therapeutic modalities the prognosis of patients with recurrent or metastatic brain tumors is still poor. New strategies such as high dose chemotherapy (HDCT) with autologous blood stem cell transplantation (ABSCT) offer the possibility to improve the longterm prognosis of these patients. Following conventional chemotherapy with carboplatin/etoposide and after achieving complete or partial remission (CR or PR) 10 patients aged from 3.2 to 25.5 years (median, 10.3 years) with refractory or recurrent malignant brain tumors (anaplastic astrocytoma/glioblastoma, n = 2; medulloblastoma/PNET, n = 6; ependymoma, n = 1; plexus carcinoma, n = 1) received in a pilot study one course of HDCT with ABSCT. The consolidation regimen consisted of thiotepa (400-600mg/m2/d, i.v. 6 h, d-9), carboplatin and etoposide (500mg/m2/d, CVI 24h, d-8 to d-5, respectively) and was followed by the retransfusion of autologous blood stem cells on day 0. Before starting HDCT 6 patients showed CR and 4 patients had PR or stable disease (SD). Following the HDCT 3 of the 4 patients with residual tumor had CR or PR. 6 patients have remained in continuous CR or SD 8 to 41 months (median 17.2 months) after the HDCT. 2 patients relapsed 8.5 and 9.5 months after HDCT and died from progressive disease. Two patients died therapy-related from systemic aspergillosis and were not evaluable for response. Hematological recovery with an absolute neutrophile count of > 0.5 x 10(9)/l and a platelet count of > 30 x 10(9)/l was reached on days +11 (median; range, +9 to +14) and +16 (median; range, +6 to +47), respectively. The main nonhematological toxic effects were infections, severe mucositis, and hyperbilirubinemia. Although the long-term efficacy of HDCT with ABSCT is still not evaluable and the toxicity of this regimen is high, a multicenter phase II trial seems to be justified in view of the poor prognosis of recurrent or refractory brain tumors in children and adolescents.