Pediatric Dent disease presenting with rickets and end-stage renal disease: case report and literature review.

Dent disease is a rare disease with proximal renal tubular dysfunction, and is characterized by low-molecular-weight proteinuria, hypercalciuria, nephrocalcinosis, nephrolithiasis, and chronic kidney disease. Renal failure slowly progresses and end-stage renal disease may develop in the late decades of life. We report a case of a 15-year-old boy who was diagnosed with Dent disease 1 with a CLCN5 truncating mutation. The patient presented with arthralgia and rickets at the onset of Dent disease and he was diagnosed with end-stage renal disease at the age of 15 years. His only symptoms were arthralgia and rickets during the disease course. The findings in this case suggest that patients with arthralgia and rickets could have a rare cause such as Dent disease.

A Focus on the Proximal Tubule Dysfunction in Dent Disease Type 1.

Dent disease type 1 is a rare X-linked recessive inherited renal disorder affecting mainly young males, generally leading to end-stage renal failure and for which there is no cure. It is caused by inactivating mutations in the gene encoding ClC-5, a 2Cl-/H+ exchanger found on endosomes in the renal proximal tubule. This transporter participates in reabsorbing all filtered plasma proteins, which justifies why proteinuria is commonly observed when ClC-5 is defective. In the context of Dent disease type 1, a proximal tubule dedifferentiation was shown to be accompanied by a dysfunctional cell metabolism. However, the exact mechanisms linking such alterations to chronic kidney disease are still unclear. In this review, we gather knowledge from several Dent disease type 1 models to summarize the current hypotheses generated to understand the progression of this disorder. We also highlight some urinary biomarkers for Dent disease type 1 suggested in different studies.

4-Phenylbutyric Acid Treatment Reduces Low-Molecular-Weight Proteinuria in a Clcn5 Knock-in Mouse Model for Dent Disease-1.

Dent disease-1 (DD-1) is a rare X-linked tubular disorder characterized by low-molecular-weight proteinuria (LMWP), hypercalciuria, nephrolithiasis and nephrocalcinosis. This disease is caused by inactivating mutations in the CLCN5 gene which encodes the voltage-gated ClC-5 chloride/proton antiporter. Currently, the treatment of DD-1 is only supportive and focused on delaying the progression of the disease. Here, we generated and characterized a Clcn5 knock-in mouse model that carries a pathogenic CLCN5 variant, c. 1566_1568delTGT; p.Val523del, which has been previously detected in several DD-1 unrelated patients, and presents the main clinical manifestations of DD-1 such as high levels of urinary b2-microglobulin, phosphate and calcium. Mutation p.Val523del causes partial ClC-5 retention in the endoplasmic reticulum. Additionally, we assessed the ability of sodium 4-phenylbutyrate, a small chemical chaperone, to ameliorate DD-1 symptoms in this mouse model. The proposed model would be of significant value in the investigation of the fundamental pathological processes underlying DD-1 and in the development of effective therapeutic strategies for this rare condition.

Dens evagination and complete invagination in the same tooth with extraoral fistula: A rare case report.

Key Clinical Message: Successful management of a rare case involving both dens evaginatus and dens invaginatus in the same tooth, monitored over a 24-month follow-up. Abstract: Dens invaginatus (DI) is a congenital dental anomaly characterized by the presence of a tooth that resembles a "tooth within a tooth." Conversely, dens evaginatus (DE) is a developmental anomaly distinguished by an additional tubercle or cusp on the tooth's crown. Both DI and DE can result in pulpal and periapical diseases in the affected tooth. This article presents a case of a healthy 14-year-old male with recurrent swelling under the chin and a wound with pus drainage on the right side of the submental area, associated with his left mandibular lateral incisor affected by both DI and DE. Clinical and radiographic examinations revealed that the tooth was necrotic and had a chronic apical abscess. Cone beam computed tomography (CBCT) confirmed Oehlers' type III DI and a talon cusp on the lingual surface of the same tooth. The patient underwent orthograde endodontic treatment. Passive ultrasonic activation of a 5.25% NaOCl solution and a mixture of Ca(OH)2 and a 2% chlorhexidine solution were utilized to effectively clean and eliminate the persistent pus discharge. After the resolution of the patient's symptoms, the apical third of the root canal and the invaginated space were filled with a plug of mineral trioxide aggregate (MTA), while the remaining root canal was filled using a sealer-based obturation technique. A 24-month follow-up visit revealed complete bone regeneration in the previously affected periradicular tissues.

A novel transgenic mouse model highlights molecular disruptions involved in the pathogenesis of Dent disease 1.

Dent disease (DD) is a hereditary renal disorder characterized by low molecular weight (LMW) proteinuria and progressive renal failure. Inactivating mutations of the CLCN5 gene encoding the 2Cl-/H+exchanger ClC-5 have been identified in patients with DD type 1. ClC-5 is essentially expressed in proximal tubules (PT) where it is thought to play a role in maintaining an efficient endocytosis of LMW proteins. However, the exact pathological roles of ClC-5 in progressive dysfunctions observed in DD type 1 are still unclear. To address this issue, we designed a mouse model carrying the most representative type of ClC-5 missense mutations found in DD patients. These mice showed a characteristic DD type 1 phenotype accompanied by altered endo-lysosomal system and autophagy functions. With ageing, KI mice showed increased renal fibrosis, apoptosis and major changes in cell metabolic functions as already suggested in previous DD models. Furthermore, we made the interesting new discovery that the Lipocalin-2-24p3R pathway might be involved in the progression of the disease. These results suggest a crosstalk between the proximal and distal nephron in the pathogenesis mechanisms involved in DD with an initial PT impairment followed by the Lipocalin-2 internalisation and 24p3R overexpression in more distal segments of the nephron. This first animal model of DD carrying a pathogenic mutation of Clcn5 and our findings pave the way aimed at exploring therapeutic strategies to limit the consequences of ClC-5 disruption in patients with DD type 1 developing chronic kidney disease.

Impact of prosthetic rehabilitation on oral health-related quality of life of Saudi Adults: A prospective observational study with pre-post design.

This study aimed to assess the impact of prosthetic treatment on the quality of life of partially/completely edentulous patients through the Oral Health Impact Profile-14 (OHIP-14) scale. This pre-post observational study was conducted in the College of Dentistry, Imam Abdulrahman Bin Faisal University, Saudi Arabia, between November 2022 and September 2023. Eligible participants were those aged between 26 and 80, in need of prosthetic treatment, and able to complete the questionnaire voluntarily. The questionnaire presented to the patients had two sections; the first included demographic and dentures-related variables, and the second included the OHIP-14 questionnaire. Differences in overall OHIP-14 scores after treatment about demographic and prosthesis-related factors were assessed using the Mann-Whitney U test/Kruskal Wallis test with a significance level of 0.05. Out of 108 participants, 65 were males, and 43 were females with an average age of 52 years with different prosthetic treatments (13.9 % fixed prostheses, 43.5 % removable partial, and 42.6 % complete dentures). 59.3 % brushed their teeth twice or more daily, and only 36.1 % checked them regularly. Comparison between the OHIP-14 items before and after treatment revealed that subjects exhibited improvement in all the domains. OHIP-14 scores did not differ significantly in terms of age, gender, and education after treatment. OHIP-14 score was considerably higher for patients with medical conditions (P = 0.007) and among complete denture wearers compared to patients with fixed prostheses (P = 0.025). Prosthetic treatment positively impacts oral health-related quality of life (OHRQoL), which improved after treatment, particularly in the social domain. There was an association between patients' medical condition, prosthesis type, and OHIP-14 score.

Dent's Disease: A Cause of Monogenic Kidney Stones and Nephrocalcinosis.

Kidney stones are becoming increasingly common, affecting up to 10% of adults. A small percentage are of monogenic origin, such as Dent's disease (DD). DD is a syndrome that causes low-molecular-weight proteinuria, hypercalciuria, nephrolithiasis, and nephrocalcinosis. It is X-linked, and most patients have mutations in the CLCN5 gene. We performed a review of the literature and evaluated the case series (n = 6) of a single center in Spain, reviewing the natural evolution of kidney stones, clinical implications, laboratory analyses, radiological development, and treatment. All patients had a genetically confirmed diagnosis, with the CLCN5 mutation being the most frequent (66%). All patients had proteinuria and albuminuria, while only two and three presented hypercalciuria and phosphate abnormalities, respectively. Only one patient did not develop lithiasis, with most (60%) requiring extracorporeal shock wave lithotripsy or surgery during follow-up. Most of the patients are under nephrological follow-up, and two have either received a renal transplant or are awaiting one. The management of these patients is similar to that with lithiasis of non-monogenic origin, with the difference that early genetic diagnosis can help avoid unnecessary treatments, genetic counseling can be provided, and some monogenic kidney stones may benefit from targeted treatments.

A female patient with Dent disease due to skewed X-chromosome inactivation.

X-linked proximal tubulopathies are rare diseases that predominantly affect men. Women are generally carriers and clinical or biochemical manifestations are usually absent or mild. We present the case of a young woman who presented with a full phenotype of Dent disease type 1 due to a de novo mutation in the CLCN5 gene and a skewed X-chromosome inactivation. Although cases of overt Dent disease type 2 and Lowe syndrome in women have been described in the literature, to our knowledge this is the first case of overt Dent disease type 1.

Clinical features and genetic analysis of 15 Chinese children with dent disease.

OBJECTIVE:  The clinical characteristics, genetic mutation spectrum, treatment strategies and prognoses of 15 children with Dent disease were retrospectively analyzed to improve pediatricians' awareness of and attention to this disease. METHODS:  We analyzed the clinical and laboratory data of 15 Chinese children with Dent disease who were diagnosed and treated at our hospital between January 2017 and May 2023 and evaluated the expression of the CLCN5 and OCRL1 genes. RESULTS:  All 15 patients were male and complained of proteinuria, and the incidence of low-molecular-weight proteinuria (LMWP) was 100.0% in both Dent disease 1 (DD1) and Dent disease 2 (DD2) patients. The incidence of hypercalciuria was 58.3% (7/12) and 66.7% (2/3) in DD1 and DD2 patients, respectively. Nephrocalcinosis and nephrolithiasis were found in 16.7% (2/12) and 8.3% (1/12) of DD1 patients, respectively. Renal biopsy revealed focal segmental glomerulosclerosis (FSGS) in 1 patient, minimal change lesion in 5 patients, and small focal acute tubular injury in 1 patient. A total of 11 mutations in the CLCN5 gene were detected, including 3 missense mutations (25.0%, c.1756C > T, c.1166T > G, and c.1618G > A), 5 frameshift mutations (41.7%, c.407delT, c.1702_c.1703insC, c.137delC, c.665_666delGGinsC, and c.2200delG), and 3 nonsense mutations (25.0%, c.776G > A, c.1609C > T, and c.1152G > A). There was no significant difference in age or clinical phenotype among patients with different mutation types (p > 0.05). All three mutations in the OCRL1 gene were missense mutations (c.1477C > T, c.952C > T, and c.198A > G). CONCLUSION:  Pediatric Dent disease is often misdiagnosed. Protein electrophoresis and genetic testing can help to provide an early and correct diagnosis.

The Apical Endocytic-Lysosomal Apparatus in CLCN5 Mutations with Phenotypic-Genotypic Correlations in Three Cases.

Dent disease type 1 is characterized by pathogenic CLCN5 gene variants and impaired receptor-mediated endocytosis in proximal tubules. However, mutation-related abnormalities in proximal tubules have not yet been described. Here, we present three patients with CLCN5 alterations and distinct morphological changes of the apical endocytic-lysosomal apparatus. The proximal tubular ultrastructure was investigated in kidney biopsy samples of three boys genotyped for non-nephrotic proteinuria. Controls: seven patients with nephrotic-range glomerular proteinuria. The genotyping findings revealed an already-known missense mutation in one patient and hitherto undescribed frameshift variants in two patients. Low-molecular-weight proteinuria, focal global glomerulosclerosis, proximal tubular changes, and tubular calcium deposits characterized each case. Three subsets of proximal tubular cells were observed: those without any abnormality, those with aplasia of apical endocytic-lysosomal apparatus and shrinkage of cells, and those with hypoplasia of apical endocytic apparatus, accumulation of proteinaceous substance in dysmorphic lysosomes, and dysmorphic mitochondria. The distribution of subsets varied from patient to patient. In one patient with a frameshift variant, an oxidative stress-like injury of proximal tubular cells and podocytes accompanied the above-mentioned alterations. Focal aplasia/hypoplasia of apical endocytic apparatus and subsequent changes in cytoplasmic organelles characterized proximal tubules in the CLCN5 pathogenic variants.

Prenatal diagnosis of dent disease type I with a nonsense pathogenic variant in CLCN5: a case study.

INTRODUCTION: Dent disease type I is a rare X-linked recessive renal tubular disease resulting from pathogenic variants in the CLCN5 gene. Due to the rarity of Dent disease type I and the diversity of its phenotypes, its clinical diagnosis is complex and poses a challenge to clinicians. METHODS: A foetus and a child from a 36-year-old pregnant woman with a birth history of abnormal children were enrolled in this study. Pregnant women undergo amniocentesis for prenatal diagnosis at the gestational age of 12+ 3 weeks. Chromosomal microarray (CMA) analysis and whole-exome sequencing (WES) were employed to investigate the chromosomal copy number and single gene variants. Literature retrieval and data analysis were performed for genotype and phenotype collection analysis. RESULTS: No chromosomal abnormalities or CNVs were detected in the entire family through karyotype and familial CMA analyses. WES identified a nonsense pathogenic variant in CLCN5 of the X chromosome, c.1942 C > T (exon 11, NM_000084), which was inherited from his mother, who exhibited regular clinical features. CONCLUSION: This study suggests that children with low-molecular-weight proteinuria and hypercalciuria should undergo prompt genetic testing to exclude Dent disease.

Dent disease 1-linked novel CLCN5 mutations result in aberrant location and reduced ion currents.

Dent disease is a rare renal tubular disease with X-linked recessive inheritance characterized by low molecular weight proteinuria (LMWP), hypercalciuria, and nephrocalcinosis. Mutations disrupting the 2Cl-/1H+ exchange activity of chloride voltage-gated channel 5 (CLCN5) have been causally linked to the most common form, Dent disease 1 (DD1), although the pathophysiological mechanisms remain unclear. Here, we conducted the whole exome capture sequencing and bioinformatics analysis within our DD1 cohort to identify two novel causal mutations in CLCN5 (c.749 G > A, p. G250D, c.829 A > C, p. T277P). Molecular dynamics simulations of ClC-5 homology model suggested that these mutations potentially may induce structural changes, destabilizing ClC-5. Overexpression of variants in vitro revealed aberrant subcellular localization in the endoplasmic reticulum (ER), significant accumulation of insoluble aggregates, and disrupted ion transport function in voltage clamp recordings. Moreover, human kidney-2 (HK-2) cells overexpressing either G250D or T277P displayed higher cell-substrate adhesion, migration capability but reduced endocytic function, as well as substantially altered transcriptomic profiles with G250D resulting in stronger deleterious effects. These cumulative findings supported pathogenic role of these ClC-5 mutations in DD1 and suggested a cellular mechanism for disrupted renal function in Dent disease patients, as well as a potential target for diagnostic biomarker or therapeutic strategy development.

A Case of Dent Disease in Children Presenting with Massive Proteinuria / 罕见病研究

This article reported the diagnosis and treatment of a boy with Dent disease presenting with massive proteinuria.He was 3 years old and found to have massive proteinuria during routine physical examination without hypoalbuminemia, urine protein electrophoresis indicated mainly low molecular weight proteins, with hypercalciuria, and metabolic acidosis, no diabetes, no amino acid urine, and renal ultrasound showed no renal calcium deposition, He had no mental and physical developmental delay and no abnormal family history. Gene detection revealed one missense mutation in exon 15 of the OCRL1 gene, c.1477C > T (p.Arg493Trp). After the diagnosis was confirmed, restrictions in dietary intake of calcium, sodium, and oxalate was restricted and oral potassium citrate and hydrochlorothiazide was prescribed. During two months of follow-up, we observed a decrease in urinary calcium levels and normal renal function. This article aims to improve the understanding of this disease among physicians and provide reference for the diagnosis and treatment of this disease through typical case report and review of previous literatures.

A Case of Dent Disease in Children Presenting with Massive Proteinuria / 罕见病研究

This article reported the diagnosis and treatment of a boy with Dent disease presenting with massive proteinuria.He was 3 years old and found to have massive proteinuria during routine physical examination without hypoalbuminemia, urine protein electrophoresis indicated mainly low molecular weight proteins, with hypercalciuria, and metabolic acidosis, no diabetes, no amino acid urine, and renal ultrasound showed no renal calcium deposition, He had no mental and physical developmental delay and no abnormal family history. Gene detection revealed one missense mutation in exon 15 of the OCRL1 gene, c.1477C > T (p.Arg493Trp). After the diagnosis was confirmed, restrictions in dietary intake of calcium, sodium, and oxalate was restricted and oral potassium citrate and hydrochlorothiazide was prescribed. During two months of follow-up, we observed a decrease in urinary calcium levels and normal renal function. This article aims to improve the understanding of this disease among physicians and provide reference for the diagnosis and treatment of this disease through typical case report and review of previous literatures.

[Determination of severity of harm caused to health in depressed skull deformation by «ping-pong¼ type in an infant]. / Opredelenie stepeni tyazhesti vreda, prichinennogo zdorov'yu, pri vdavlennoi deformatsii cherepa po tipu «ping-pong¼ u mladentsa.

THE OBJECTIVE: Is to develop a differential approach to determining the severity of harm caused to health in case of depressed skull injuries in infants, depending on their morphological features and the character of required treatment. The material included data from literature sources on the study of brain injuries in infants, clinical guidelines, describing the features of clinical picture and diagnosis of depressed skull fractures in infants and legal and regulatory framework of forensic medical evaluation of harm caused to health in injury. The following methods of research were used: logical-analytical, logical-synthetic (generalization), comparative, system-analytical (analysis of relations between facts) and radiological method. An algorithm for determining the severity of harm caused to health in depressed skull deformations by «ping-pong¼ type in an infant is proposed for discussion. The algorithm is based on the data from injury imaging techniques, including X-ray computed tomography, takes into account the clinical picture and the availability of indications for surgical treatment, and will allow to objectively assess the severity of harm caused to health in such cases.

A missense mutant of ocrl1 promotes apoptosis of tubular epithelial cells and disrupts endocytosis and the cell cycle of podocytes in Dent-2 Disease.

BACKGROUND: This study aimed to identify an orcl1 mutation in a patient with Dent-2 Disease and investigate the underlying mechanisms. METHODS: The ocrl1 mutation was identified through exome sequencing. Knockdown of orcl1 and overexpression of the orcl1 mutant were performed in HK-2 and MPC5 cells to study its function, while flow cytometry measured reactive oxygen species (ROS), phosphatidylserine levels, and cell apoptosis. Scanning electron microscopy observed crystal adhesion, while transmission electron microscopy examined kidney tissue pathology. Laser scanning confocal microscopy was used to examine endocytosis, and immunohistochemical and immunofluorescence assays detected protein expression. Additionally, podocyte-specific orcl1 knockout mice were generated to investigate the role of orcl1 in vivo. RESULTS: We identified a mutation resulting in the replacement of Histidine with Arginine at position 318 (R318H) in ocrl1 in the proband. orcl1 was widely expressed in the kidney. In vitro experiments showed that knockdown of orcl1 and overexpression of ocrl1 mutant increased ROS, phosphatidylserine exocytosis, crystal adhesion, and cell apoptosis in HK-2 cells. Knockdown of orcl1 in podocytes reduced endocytosis and disrupted the cell cycle while increasing cell migration. In vivo studies in mice showed that conditional deletion of orcl1 in podocytes caused glomerular dysfunction, including proteinuria and fibrosis. CONCLUSION: This study identified an R318H mutation in orcl1 in a patient with Dent-2 Disease. This mutation may contribute to renal injury by promoting ROS production and inducing cell apoptosis in tubular cells, while disrupting endocytosis and the cell cycle, and promoting cell migration of podocytes. Video Abstract.

A Case of Hidradenitis Suppurativa in a Genetically Confirmed Lowe Syndrome Patient.

Lowe syndrome (LS), also known as oculocerebrorenal syndrome, is an X-linked multisystemic disorder caused by mutations in OCRL1, which encodes a member of the inositol-5-phosphatase family. As implied by its name, congenital cataracts, defects in the central nervous system, and renal manifestations are the main symptoms. Early hidradenitis suppurativa (HS) occurrence in Dent disease 2 (DD2), which is a mild variant of LS and shares the OCRL1 gene mutation, has been reported, although not in LS patients. Here, we report a case of HS in a 17-year-old boy with genetically confirmed LS, which suggests that defects in the OCRL1 gene may contribute to HS pathogenesis.

Characterization of pre-mRNA Splicing Defects Caused by CLCN5 and OCRL Mutations and Identification of Novel Variants Associated with Dent Disease.

Dent disease (DD) is an X-linked renal tubulopathy characterized by low-molecular-weight proteinuria, hypercalciuria, nephrocalcinosis, nephrolithiasis and progressive renal failure. Two-thirds of cases are associated with inactivating variants in the CLCN5 gene (Dent disease 1, DD1) and a few present variants in the OCRL gene (Dent disease 2, DD2). The aim of the present study was to test the effect on the pre-mRNA splicing process of DD variants, described here or in the literature, and describe the clinical and genotypic features of thirteen unrelated patients with suspected DD. All patients presented tubular proteinuria, ten presented hypercalciuria and five had nephrolithiasis or nephrocalcinosis. CLCN5 and OCRL genes were analyzed by Sanger sequencing. Nine patients showed variants in CLCN5 and four in OCRL; eight of these were new. Bioinformatics tools were used to select fifteen variants with a potential effect on pre-mRNA splicing from our patients' group and from the literature, and were experimentally tested using minigene assays. Results showed that three exonic missense mutations and two intronic variants affect the mRNA splicing process. Our findings widen the genotypic spectrum of DD and provide insight into the impact of variants causing DD.

Recurring renal lithiasis due to Dent's disease.

Dent's disease is a rare cause of hypercalciuria and recurring urolithiasis. Patients with this disease have elevated bone resorption due to the presence of parathormone (PTH) in the urine. We describe the case of a 21-year-old male with hypercalciuria, elevated bone resorption and recurring bilateral urolithiasis that achieves radiological and clinical stability with percutaneous nephrolithotomy (PNL) and medical treatment with hydrochlorothiazide, potassium-citrate and phytate.

A novel likely pathogenic CLCN5 variant in Dent's disease.

BACKGROUND: The majority of cases of Dent's disease are caused by pathogenic variants in the CLCN5 gene, which encodes a voltage-gated chloride ion channel (ClC-5), resulting in proximal tubular dysfunction. We present three members of the same family and one unrelated paediatric patient with the same insertion-deletion CLCN5 variant. The identification of these patients and positive familial segregation led to the re-classification of this variant from one of unknown significance to one of likely pathogenicity. CASE PRESENTATION: A 41 year old male presented with end stage kidney failure, proteinuria and haematuria. Whole genome sequencing identified an insertion-deletion variant in CLCN5, resulting in a missense change (c.1744_1745delinsAA p.(Ala582Lys)). His brother and nephew, who both exhibited renal impairment, haematuria, proteinuria, glycosuria and nephrocalcinosis, were found to have the same variant. In addition, genetic testing of an unrelated paediatric patient who presented with proteinuria and hypercalciuria, demonstrated the same variant. CONCLUSIONS: The identification of this novel variant in four individuals with features of Dent's disease, has led to the re-classification of the variant to one of likely pathogenicity. As a result, our patients and any future patients with the same variant can be offered a likely diagnosis, without the need for kidney biopsy, and their family members can be offered genetic screening.