Pathophysiological Role of K2P Channels in Human Diseases.

The family of two-pore domain potassium (K2P) channels is critically involved in central cellular functions such as ion homeostasis, cell development, and excitability. K2P channels are widely expressed in different human cell types and organs. It is therefore not surprising that aberrant expression and function of K2P channels are related to a spectrum of human diseases, including cancer, autoimmune, CNS, cardiovascular, and urinary tract disorders. Despite homologies in structure, expression, and stimulus, the functional diversity of K2P channels leads to heterogeneous influences on human diseases. The role of individual K2P channels in different disorders depends on expression patterns and modulation in cellular functions. However, an imbalance of potassium homeostasis and action potentials contributes to most disease pathologies. In this review, we provide an overview of current knowledge on the role of K2P channels in human diseases. We look at altered channel expression and function, the potential underlying molecular mechanisms, and prospective research directions in the field of K2P channels.

Role of α- and ß-adrenergic signaling in phenotypic targeting: significance in benign and malignant urologic disease.

The urinary tract is highly innervated by autonomic nerves which are essential in urinary tract development, the production of growth factors, and the control of homeostasis. These neural signals may become dysregulated in several genitourinary (GU) disease states, both benign and malignant. Accordingly, the autonomic nervous system is a therapeutic target for several genitourinary pathologies including cancer, voiding dysfunction, and obstructing nephrolithiasis. Adrenergic receptors (adrenoceptors) are G-Protein coupled-receptors that are distributed throughout the body. The major function of α1-adrenoceptors is signaling smooth muscle contractions through GPCR and intracellular calcium influx. Pharmacologic intervention of α-and ß-adrenoceptors is routinely and successfully implemented in the treatment of benign urologic illnesses, through the use of α-adrenoceptor antagonists. Furthermore, cell-based evidence recently established the antitumor effect of α1-adrenoceptor antagonists in prostate, bladder and renal tumors by reducing neovascularity and impairing growth within the tumor microenvironment via regulation of the phenotypic epithelial-mesenchymal transition (EMT). There has been a significant focus on repurposing the routinely used, Food and Drug Administration-approved α1-adrenoceptor antagonists to inhibit GU tumor growth and angiogenesis in patients with advanced prostate, bladder, and renal cancer. In this review we discuss the current evidence on (a) the signaling events of the autonomic nervous system mediated by its cognate α- and ß-adrenoceptors in regulating the phenotypic landscape (EMT) of genitourinary organs; and (b) the therapeutic significance of targeting this signaling pathway in benign and malignant urologic disease. Video abstract.

TRPM8 Channels: Advances in Structural Studies and Pharmacological Modulation.

The transient receptor potential melastatin subtype 8 (TRPM8) is a cold sensor in humans, activated by low temperatures (>10, <28 °C), but also a polymodal ion channel, stimulated by voltage, pressure, cooling compounds (menthol, icilin), and hyperosmolarity. An increased number of experimental results indicate the implication of TRPM8 channels in cold thermal transduction and pain detection, transmission, and maintenance in different tissues and organs. These channels also have a repercussion on different kinds of life-threatening tumors and other pathologies, which include urinary and respiratory tract dysfunctions, dry eye disease, and obesity. This compendium firstly covers newly described papers on the expression of TRPM8 channels and their correlation with pathological states. An overview on the structural knowledge, after cryo-electron microscopy success in solving different TRPM8 structures, as well as some insights obtained from mutagenesis studies, will follow. Most recently described families of TRPM8 modulators are also covered, along with a section of molecules that have reached clinical trials. To finalize, authors provide an outline of the potential prospects in the TRPM8 field.

Intronic variant in IQGAP3 associated with hereditary neuropathy with proximal lower dominancy, urinary disturbance, and paroxysmal dry cough.

In 2008, we reported a clinically and genetically new type of autosomal dominant disorder of motor and sensory neuropathy with proximal dominancy in the lower extremities, urinary disturbance, and paroxysmal dry cough. To identify the nucleotide variant causative of this disease, we reanalyzed the linkage of the original Japanese pedigree including seven newly ascertained subjects with updated information. We assigned the locus of the disease to 1p13.3-q23 (maximum logarithm-of-odds score = 2.71). Exome sequencing for five patients and one healthy relative from the pedigree revealed 2526 patient-specific single-nucleotide variants (SNVs). By rigorous filtering processes using public databases, our linkage results, and functional prediction, followed by Sanger sequencing of the pedigree and 520 healthy Japanese individuals, we identified an intronic SNV in IQGAP3, a gene known to be associated with neurite outgrowth. Upon pathological examination of the sural nerve, moderate, chronic, mainly axonal neuropathy was observed. By histochemical analyses, we observed a patient-specific increase of IQGAP3 expression in the sural nerve. We concluded that the variant of IQGAP3 is associated with the disease in our pedigree.

Dysfunctional bladder neurophysiology in urofacial syndrome Hpse2 mutant mice.

AIMS: Urofacial syndrome (UFS) is an autosomal recessive disease characterized by detrusor contraction against an incompletely dilated outflow tract. This dyssynergia causes dribbling incontinence and incomplete voiding. Around half of individuals with UFS have biallelic mutations of HPSE2 that encodes heparanase 2, a protein found in pelvic ganglia and bladder nerves. Homozygous Hpse2 mutant mice have abnormal patterns of nerves in the bladder body and outflow tract, and also have dysfunctional urinary voiding. We hypothesized that bladder neurophysiology is abnormal Hpse2 mutant mice. METHODS: Myography was used to study bladder bodies and outflow tracts isolated from juvenile mice. Myogenic function was analyzed after chemical stimulation or blockade of key receptors. Neurogenic function was assessed by electrical field stimulation (EFS). Muscarinic receptor expression was semi-quantified by Western blot analysis. RESULTS: Nitrergic nerve-mediated relaxation of precontracted mutant outflow tracts was significantly decreased vs littermate controls. The contractile ability of mutant outflow tracts was normal as assessed by KCl and the α1-adrenoceptor agonist phenylephrine. EFS of mutant bladder bodies induced significantly weaker contractions than controls. Conversely, the muscarinic agonist carbachol induced significantly stronger contractions of bladder body than controls. CONCLUSIONS: The Hpse2 model of UFS features aberrant bladder neuromuscular physiology. Further work is required to determine whether similar aberrations occur in patients with UFS.

Heparanase 2 and Urofacial Syndrome, a Genetic Neuropathy.

Urofacial syndrome (UFS) is a rare but potentially devastating autosomal recessive disease. It comprises both incomplete urinary bladder emptying and a facial grimace upon smiling. A subset of individuals with the disease has biallelic mutations of HPSE2, coding for heparanase-2. Heparanase-2 and the classical heparanase are both detected in nerves in the maturing bladder, and mice mutant for Hpse2 have UFS-like bladder voiding defects and abnormally patterned bladder nerves. Other evidence suggests that the heparanase axis plays several roles in the peripheral and central nervous systems, quite apart from UFS-related biology. Some individuals with UFS lack HPSE2 mutations and instead carry biallelic variants of LRIG2, encoding leucine-rich-repeats and immunoglobulin-like-domains 2. Like heparanase-2, LRIG2 is detected in bladder nerves, and mutant Lrig2 mice have urination defects and abnormal patterns of bladder nerves. Further work is now needed to define the precise roles of heparanase-2 and LRIG2 in normal and abnormal neural differentiation.

Hpa2 Gene Cloning.

From 1999-2003, Oxford GlycoSciences (OGS) ran a successful drug discovery oncology programme to discover small molecule inhibitors of the Heparanase I enzyme (HPSE1). HPSE1 at the time was widely regarded as being the sole mammalian enzyme capable of cleaving Heparan Sulfate (HS). A second family protein member however called Heparanase 2 (HPSE2) including splice forms was subsequently discovered by PCR analysis based on EST sequences. HPSE2 was found to be expressed mainly in smooth muscle containing tissues, particularly bladder and brain. HPSE2 is poorly expressed in haematopoietic cells and placenta which contrasts with the HPSE1 distribution pattern. HPSE2 binds more strongly to HS than HPSE1 and is believed to out compete for substrate binding and so in effect act as a tumor suppressor. So far, all attempts to show specific HPSE2 endoglycosidase activity against HS have failed suggesting that the enzyme may act as a pseudoenzyme that has evolved to retain only certain non-catalytic heparanase like functions. A breakthrough in the elucidation of functional roles for HPSE2 came about in 2010 with the linkage of HPSE2 gene deletions and mutations to the development of Ochoa/Urofacial Syndrome. Future work into the mechanistic analysis of HPSE2's role in signalling, tumor suppression and bladder/nerve functioning are needed to fully explore the role of this family of proteins.

Lrig2 and Hpse2, mutated in urofacial syndrome, pattern nerves in the urinary bladder.

Mutations in leucine-rich-repeats and immunoglobulin-like-domains 2 (LRIG2) or in heparanase 2 (HPSE2) cause urofacial syndrome, a devastating autosomal recessive disease of functional bladder outlet obstruction. It has been speculated that urofacial syndrome has a neural basis, but it is unknown whether defects in urinary bladder innervation are present. We hypothesized that urofacial syndrome features a peripheral neuropathy of the bladder. Mice with homozygous targeted Lrig2 mutations had urinary defects resembling those found in urofacial syndrome. There was no anatomical blockage of the outflow tract, consistent with a functional bladder outlet obstruction. Transcriptome analysis revealed differential expression of 12 known transcripts in addition to Lrig2, including 8 with established roles in neurobiology. Mice with homozygous mutations in either Lrig2 or Hpse2 had increased nerve density within the body of the urinary bladder and decreased nerve density around the urinary outflow tract. In a sample of 155 children with chronic kidney disease and urinary symptoms, we discovered novel homozygous missense LRIG2 variants that were predicted to be pathogenic in 2 individuals with non-syndromic bladder outlet obstruction. These observations provide evidence that a peripheral neuropathy is central to the pathobiology of functional bladder outlet obstruction in urofacial syndrome, and emphasize the importance of LRIG2 and heparanase 2 for nerve patterning in the urinary tract.

Current Therapeutic Strategies in Clinical Urology.

The field of urology encompasses all benign and malignant disorders of the urinary tract and the male genital tract. Urological disorders convey a huge economic and patient quality-of-life burden. Hospital acquired urinary tract infections, in particular, are under scrutiny as a measure of hospital quality. Given the prevalence of these pathologies, there is much progress still to be made in available therapeutic options in order to minimize side effects and provide effective care. Current drug delivery mechanisms in urological malignancy and the benign urological conditions of overactive bladder (OAB), interstitial cystitis/bladder pain syndrome (IC/BPS), and urinary tract infection (UTI) will be reviewed herein. Both systemic and local therapies will be discussed including sustained release formulations, nanocarriers, hydrogels and other reservoir systems, as well as gene and immunotherapy. The primary focus of this review is on agents which have passed the preclinical stages of development.

[Detection of mutations of the HNF1B gene in children with congenital anomalies of the kidney and urinary tract]. / Detección de mutaciones del gen de HNF1B en niños con malformaciones congénitas renales y del tracto urinario.

INTRODUCTION: Congenital anomalies of the kidney and urinary tract are caused by genetic alterations mostly unknown. Mutations in the gene that codes for hepatocyte nuclear factor 1B (HNF1B) are the most frequently described monogenic causes. Data are unknown in Chile and Latin America. OBJECTIVE: To determine the presence of variants of the HNF1B gene in Chilean children with conge nital anomalies of the kidney and/or the urinary tract and their clinical characteristics. PATIENTS AND METHOD: Descriptive study with children aged 10 months to 17 years, patients of the Calvo Mackenna Hospital Nephrology Unit, with cystic renal dysplasia, non cystic renal dysplasia/hypoplasia, horses hoe kidney between April and December 2016. HNF1B variants were determined by sequencing of exons 1, 2, 3 and 4 after DNA extraction and amplification. Restriction enzymes were used to define if the variants were homo or heterozygous. Direct family members of index cases were studied with sequencing of the affected exon. RESULTS: 32 patients were included, 43.75% males, median age 11 years. 65.6% of them had non-cystic renal dysplasia, 31.25% cystic renal dysplasia, and 3.15% hor seshoe kidney. In two patients (6.25%) the same heterozygous genetic variant was detected in exon 4, position 1027 (C1027T), not previously described. The study of relatives found the same variant in three out of five individuals, all without congenital nephro-urological anomalies. CONCLUSIONS: We confirmed the presence of a not previously described heterozygous genetic variant of the HNF1B gene. This work initiates the search for this type of mutations in our region which allows us to ap proach the knowledge of causality, determination of extrarenal involvement, and genetic counseling.

A mouse model of urofacial syndrome with dysfunctional urination.

Urofacial syndrome (UFS) is an autosomal recessive disease with severe dysfunctional urination including urinary incontinence (UI). Biallelic mutations of HPSE2 are discovered from UFS patients, suggesting that HPSE2 is a candidate disease gene. Here, we show that deletion of Hpse2 is sufficient to cause the UFS-like phenotype in mice. Hpse2 knockout mutants display a distended bladder (megacystis) phenotype and abnormal voiding behavior similar to that found in patients. While Hpse2 is largely dispensable for detrusor smooth muscle and urothelial cell fate determination, the mutants have significantly lower rates of cell proliferation than wild-type littermate controls. All Hpse2 mutants have a growth retardation phenotype and die within a month after birth. Comprehensive blood chemistry and urinalysis indicate that Hpse2 mutants have renal dysfunction and malnutrition. We provide evidence that transforming growth factor beta (Tgfß) signaling is attenuated at birth. However, Tgfß activity is significantly enhanced at later stages when the urological phenotype is severe, and the mutant bladders have accumulated excessive amount of fibrotic tissue. Together, these findings strongly suggest that Hpse2 is a causative gene of human UFS and further uncover unexpected roles of Hpse2 in bladder physiology, tissue remodeling and Tgfß signaling.

SOCS3 Immunohistochemical Expression Seems to Support the 2005 and 2014 International Society of Urological Pathology (ISUP) Modified Gleason Grading System.

BACKGROUND: In the 2014, The International Society of Urological Pathology (ISUP) consensus conference update the grading of prostate, last revised in 2005. In this study we evaluate the SOCS3 immunohistochemical protein expression in different Gleason prostatic adenocarcinoma: classical Gleason grade 3, classical Gleason grade 3 upgraded to Gleason grade 4 according to the ISUP modifications and classical and modified Gleason grade 4. The major conclusions were: (i) Cribriform glands should be assigned a Gleason pattern 4, regardless of morphology; (ii) Glomeruloid glands should be assigned a Gleason pattern 4, regardless of morphology; (iii) Grading of mucinous carcinoma of the prostate should be based on its underlying growth pattern rather than all as pattern 4; and (iv) Intraductal carcinoma of the prostate without invasive carcinoma should not assigned Gleason grade and a comment about aggressive carcinoma probably associated should be made. In a recent report we analyzed the methylathion status of cytokine signaling (SOCS) proteins 3 (SOCS3) gene and the consequences of promoter hypermethylation on mRNA and protein expression in a collection of prostate cancer and benign prostate hyperplasia (BPH) and for the first time we demonstrated that a hypermethylation of SOCS3 with a significant reduction of its mRNA and protein expression identifies a subgroup of prostate cancer with a more aggressive behavior. Moreover we demonstrated that the immunohystochemical analysis of SOCS3 protein expression in prostatic cancer biopsies may provide a useful and easier method than SOCS3 methylation analysis to individuate in cancer with intermediate-high grade Gleason score a subgroup of prostate cancer with a more aggressive behavior. METHODS: A total of 148 radical prostatectomy with diagnosis of prostatic acinar adenocarcinoma were stratified into three different categories on the basis of Gleason grade: (i) Twenty-six prostatic adenocarcinoma with classical and modified Gleason grade 3; (ii) Fifty seven prostatic adenocarcinoma with classical Gleason grade 3 upgraded to Gleason grade 4 by 2005 and 2014 ISUP Consensus Conference; and (iii) Sixty five prostatic adenocarcinoma with classical and modified Gleason grade 4. Immunohistochemical analysis for SOCS3 was performed and SOCS3 staining intensity were evaluated by two pathologists in three different ways on the basis of the intensity of cytoplasmatic staining: positive (intense cytoplasmatic staining in more than 50% of neoplastic cells) (+), negative (absence of cytoplasmatic staining in more than 50% of neoplastic cells) (-), weakly positive (weak cytoplasmatic staining in more than 50% of neoplastic cells (+/-). RESULTS: In the group of prostatic adenocarcinoma Gleason grade 3 we found that SOCS3 positivity (+) were observed in 19 out of 26 cases (73.1%); in 5 out of 26 prostatic adenocarcinoma the neoplastic glands showed weak intensity SOCS3 staining (+/-) (19.2%), while in only two cases we found SOCS-3 negativity (-) (7.7%); in the group of cases with prostatic adenocarcinoma with Gleason grade 4, 16 out 65 cases (24.6%) showed SOCS3 positivity (+); 18 out 65 cases (27.7%) SOCS3 weakly positive (+/-), and in 31 cases (47.7%) SOCS3 negative staining (-) were observed. Interestingly, the group of prostatic adenocarcinoma with histological Gleason 3 pattern upgraded to Gleason 4 pattern according to the 2005 and 2014 ISUP modified grading system, showed SOCS3 positivity (+) in 16 out of 57 cases (28%), in 16 out 57 cases (28%) a weakly positive for SOCS3 (+/-) were observed, while 25 cases (44%) showed negative SOCS3 staining (-). CONCLUSIONS: In this study we demonstrated a significant association of SOCS3 positivity (+) with prostatic carcinoma classical Gleason pattern 3 (P < 0.0001), while SOCS3 negative pattern (-) or SOCS3 weakly positive pattern (+/-) were associated to prostatic carcinomas with Gleason pattern 3 upgraded to Gleason pattern 4 (P = 0.0002) and with classical Gleason pattern 4. The significant difference of SOCS3 immunohistochemical expression between classical Gleason grade 3 and Gleason grade 4 upgraded to grade 4 seems to support the definitions and the modifications of Gleason grade 4 of the 2005 and the 2014 International Society of Urological Pathology (ISUP). The hypoexpression of SOCS3 protein in glomeruloid glands could support the hypothesis that from molecular point of view this growth pattern could be different from classical Gleason pattern 3 and biologically more closely to Gleason pattern 4, confirming the conclusions of the 2014 ISUP Conference assigning a Gleason pattern 4 to glomeruloid glands regardless of morphology. Prostate 77: 597-603, 2017. © 2017 Wiley Periodicals, Inc.

Clinical implications of the microbiome in urinary tract diseases.

PURPOSE OF REVIEW: The purpose of this review is to outline and evaluate the most recent literature on the role of the microbiome in urinary tract diseases. RECENT FINDINGS: High throughput molecular DNA sequencing of bacterial 16S rRNA genes enabled the analysis of complex microbial communities inhabiting the human urinary tract. Several recent studies have identified bacterial taxa of the urinary microbiome to impact urinary tract diseases including interstitial cystitis, urgency urinary incontinence or calcium oxalate stone formation. Furthermore, treatment of urinary tract infections by antibiotics globally impacts community profiles of the intestinal microbiota and might indirectly influence human health. Alternative treatment options like application of probiotics for the treatment of urinary tract infections are currently under investigation. SUMMARY: The urinary microbiome and its relationship to urinary tract diseases is currently under comprehensive investigation. Further studies are needed to shed light on the role of commensal microbiota for urinary tract infections.

Epidermolysis Bullosa with Pyloric Atresia and Significant Urologic Involvement.

Epidermolysis bullosa (EB) is a rare inherited disease that causes epidermal fragility, blistering, and erosions. EB results from a variety of mutations in proteins of the skin and mucous membranes of the body. Mutations in plectin a protein involved in hemidesmosome integrity and function, are associated with subtypes of EB, including EB with pyloric atresia and EB with muscular dystrophy. We present two cases of EB with significant urologic involvement resulting from mutations in plectin.

A multiplexed analysis approach identifies new association of inflammatory proteins in patients with overactive bladder.

Overactive bladder (OAB) is a common debilitating bladder condition with unknown etiology and limited diagnostic modalities. Here, we explored a novel high-throughput and unbiased multiplex approach with cellular and molecular components in a well-characterized patient cohort to identify biomarkers that could be reliably used to distinguish OAB from controls or provide insights into underlying etiology. As a secondary analysis, we determined whether this method could discriminate between OAB and other chronic bladder conditions. We analyzed plasma samples from healthy volunteers (n = 19) and patients diagnosed with OAB, interstitial cystitis/bladder pain syndrome (IC/BPS), or urinary tract infections (UTI; n = 51) for proinflammatory, chemokine, cytokine, angiogenesis, and vascular injury factors using Meso Scale Discovery (MSD) analysis and urinary cytological analysis. Wilcoxon rank-sum tests were used to perform univariate and multivariate comparisons between patient groups (controls, OAB, IC/BPS, and UTI). Multivariate logistic regression models were fit for each MSD analyte on 1) OAB patients and controls, 2) OAB and IC/BPS patients, and 3) OAB and UTI patients. Age, race, and sex were included as independent variables in all multivariate analysis. Receiver operating characteristic (ROC) curves were generated to determine the diagnostic potential of a given analyte. Our findings demonstrate that five analytes, i.e., interleukin 4, TNF-α, macrophage inflammatory protein-1ß, serum amyloid A, and Tie2 can reliably differentiate OAB relative to controls and can be used to distinguish OAB from the other conditions. Together, our pilot study suggests a molecular imbalance in inflammatory proteins may contribute to OAB pathogenesis.

Heparanase 2, mutated in urofacial syndrome, mediates peripheral neural development in Xenopus.

Urofacial syndrome (UFS; previously Ochoa syndrome) is an autosomal recessive disease characterized by incomplete bladder emptying during micturition. This is associated with a dyssynergia in which the urethral walls contract at the same time as the detrusor smooth muscle in the body of the bladder. UFS is also characterized by an abnormal facial expression upon smiling, and bilateral weakness in the distribution of the facial nerve has been reported. Biallelic mutations in HPSE2 occur in UFS. This gene encodes heparanase 2, a protein which inhibits the activity of heparanase. Here, we demonstrate, for the first time, an in vivo developmental role for heparanase 2. We identified the Xenopus orthologue of heparanase 2 and showed that the protein is localized to the embryonic ventrolateral neural tube where motor neurons arise. Morpholino-induced loss of heparanase 2 caused embryonic skeletal muscle paralysis, and morphant motor neurons had aberrant morphology including less linear paths and less compactly-bundled axons than normal. Biochemical analyses demonstrated that loss of heparanase 2 led to upregulation of fibroblast growth factor 2/phosphorylated extracellular signal-related kinase signalling and to alterations in levels of transcripts encoding neural- and muscle-associated molecules. Thus, a key role of heparanase 2 is to buffer growth factor signalling in motor neuron development. These results shed light on the pathogenic mechanisms underpinning the clinical features of UFS and support the contention that congenital peripheral neuropathy is a key feature of this disorder.

LRIG2 mutations cause urofacial syndrome.

Urofacial syndrome (UFS) (or Ochoa syndrome) is an autosomal-recessive disease characterized by congenital urinary bladder dysfunction, associated with a significant risk of kidney failure, and an abnormal facial expression upon smiling, laughing, and crying. We report that a subset of UFS-affected individuals have biallelic mutations in LRIG2, encoding leucine-rich repeats and immunoglobulin-like domains 2, a protein implicated in neural cell signaling and tumorigenesis. Importantly, we have demonstrated that rare variants in LRIG2 might be relevant to nonsyndromic bladder disease. We have previously shown that UFS is also caused by mutations in HPSE2, encoding heparanase-2. LRIG2 and heparanase-2 were immunodetected in nerve fascicles growing between muscle bundles within the human fetal bladder, directly implicating both molecules in neural development in the lower urinary tract.

Two hits in one: whole genome sequencing unveils LIG4 syndrome and urofacial syndrome in a case report of a child with complex phenotype.

BACKGROUND: Ligase IV syndrome, a hereditary disease associated with compromised DNA damage response mechanisms, and Urofacial syndrome, caused by an impairment of neural cell signaling, are both rare genetic disorders, whose reports in literature are limited. We describe the first case combining both disorders in a specific phenotype. CASE PRESENTATION: We report a case of a 7-year old girl presenting with a complex phenotype characterized by multiple congenital abnormalities and dysmorphic features, microcephaly, short stature, combined immunodeficiency and severe vesicoureteral reflux. Whole Genome Sequencing was performed and a novel ligase IV homozygous missense c.T1312C/p.Y438H mutation was detected, and is believed to be responsible for most of the clinical features of the child, except vesicoureteral reflux which has not been previously described for ligase IV deficiency. However, we observed a second rare damaging (nonsense) homozygous mutation (c.C2125T/p.R709X) in the leucine-rich repeats and immunoglobulin-like domains 2 gene that encodes a protein implicated in neural cell signaling and oncogenesis. Interestingly, this mutation has recently been reported as pathogenic and causing urofacial syndrome, typically displaying vesicoureteral reflux. Thus, this second mutation completes the missing genetic explanation for this intriguing clinical puzzle. We verified that both mutations fit an autosomal recessive inheritance model due to extensive consanguinity. CONCLUSIONS: We successfully identified a novel ligase IV mutation, causing ligase IV syndrome, and an additional rare leucine-rich repeats and immunoglobulin-like domains 2 gene nonsense mutation, in the context of multiple autosomal recessive conditions due to extensive consanguinity. This work demonstrates the utility of Whole Genome Sequencing data in clinical diagnosis in such cases where the combination of multiple rare phenotypes results in very intricate clinical pictures. It also reports a novel causative mutation and a clinical phenotype, which will help in better defining the essential features of both ligase IV and leucine-rich repeats and immunoglobulin-like domains 2 deficiency syndromes.

Urinary tract effects of HPSE2 mutations.

Urofacial syndrome (UFS) is an autosomal recessive congenital disease featuring grimacing and incomplete bladder emptying. Mutations of HPSE2, encoding heparanase 2, a heparanase 1 inhibitor, occur in UFS, but knowledge about the HPSE2 mutation spectrum is limited. Here, seven UFS kindreds with HPSE2 mutations are presented, including one with deleted asparagine 254, suggesting a role for this amino acid, which is conserved in vertebrate orthologs. HPSE2 mutations were absent in 23 non-neurogenic neurogenic bladder probands and, of 439 families with nonsyndromic vesicoureteric reflux, only one carried a putative pathogenic HPSE2 variant. Homozygous Hpse2 mutant mouse bladders contained urine more often than did wild-type organs, phenocopying human UFS. Pelvic ganglia neural cell bodies contained heparanase 1, heparanase 2, and leucine-rich repeats and immunoglobulin-like domains-2 (LRIG2), which is mutated in certain UFS families. In conclusion, heparanase 2 is an autonomic neural protein implicated in bladder emptying, but HPSE2 variants are uncommon in urinary diseases resembling UFS.