RESUMO
Calcium-containing stones represent the most common form of kidney calculi, frequently linked to idiopathic hypercalciuria, though their precise pathogenesis remains elusive. This research aimed to elucidate the molecular mechanisms involved by employing urinary exosomal microRNAs as proxies for renal tissue analysis. Elevated miR-148b-5p levels were observed in exosomes derived from patients with kidney stones. Systemic administration of miR-148b-5p in rat models resulted in heightened urinary calcium excretion, whereas its inhibition reduced stone formation. RNA immunoprecipitation combined with deep sequencing identified miR-148b-5p as a suppressor of calcitonin receptor (Calcr) expression, thereby promoting urinary calcium excretion and stone formation. Mice deficient in Calcr in distal epithelial cells demonstrated elevated urinary calcium excretion and renal calcification. Mechanistically, miR-148b-5p regulated Calcr through the circRNA-83536/miR-24-3p signaling pathway. Human kidney tissue samples corroborated these results. In summary, miR-148b-5p regulates the formation of calcium-containing kidney stones via the circRNA-83536/miR-24-3p/Calcr axis, presenting a potential target for novel therapeutic interventions to prevent calcium nephrolithiasis.
Assuntos
Cálcio , Hipercalciúria , MicroRNAs , Nefrolitíase , Animais , Humanos , Masculino , Camundongos , Ratos , Cálcio/metabolismo , Exossomos/metabolismo , Exossomos/genética , Hipercalciúria/genética , Hipercalciúria/metabolismo , Hipercalciúria/patologia , Rim/metabolismo , Rim/patologia , Cálculos Renais/metabolismo , Cálculos Renais/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , MicroRNAs/genética , MicroRNAs/metabolismo , Nefrolitíase/metabolismo , Nefrolitíase/genética , Nefrolitíase/patologia , Ratos Sprague-Dawley , Transdução de SinaisRESUMO
BACKGROUND: Molecular mechanisms of kidney stone formation remain unknown in most patients. Previous studies have shown a high heritability of nephrolithiasis, but data on the prevalence and characteristics of genetic disease in unselected adults with nephrolithiasis are lacking. This study was conducted to fill this important knowledge gap. METHODS: We performed whole exome sequencing in 787 participants in the Bern Kidney Stone Registry, an unselected cohort of adults with one or more past kidney stone episodes [kidney stone formers (KSFs)] and 114 non-kidney stone formers (NKSFs). An exome-based panel of 34 established nephrolithiasis genes was analysed and variants assessed according to American College of Medical Genetics and Genomics criteria. Pathogenic (P) or likely pathogenic (LP) variants were considered diagnostic. RESULTS: The mean age of KSFs was 47 ± 15 years and 18% were first-time KSFs. A Mendelian kidney stone disease was present in 2.9% (23/787) of KSFs. The most common genetic diagnoses were cystinuria (SLC3A1, SLC7A9; n = 13), vitamin D-24 hydroxylase deficiency (CYP24A1; n = 5) and primary hyperoxaluria (AGXT, GRHPR, HOGA1; n = 3). Of the KSFs, 8.1% (64/787) were monoallelic for LP/P variants predisposing to nephrolithiasis, most frequently in SLC34A1/A3 or SLC9A3R1 (n = 37), CLDN16 (n = 8) and CYP24A1 (n = 8). KSFs with Mendelian disease had a lower age at the first stone event (30 ± 14 versus 36 ± 14 years; P = .003), were more likely to have cystine stones (23.4% versus 1.4%) and less likely to have calcium oxalate monohydrates stones (31.9% versus 52.5%) compared with KSFs without a genetic diagnosis. The phenotype of KSFs with variants predisposing to nephrolithiasis was subtle and showed significant overlap with KSFs without diagnostic variants. In NKSFs, no Mendelian disease was detected and LP/P variants were significantly less prevalent compared with KSFs (1.8% versus 8.1%). CONCLUSION: Mendelian disease is uncommon in unselected adult KSFs, yet variants predisposing to nephrolithiasis are significantly enriched in adult KSFs.
Assuntos
Cálculos Renais , Humanos , Cálculos Renais/genética , Cálculos Renais/epidemiologia , Cálculos Renais/etiologia , Feminino , Masculino , Prevalência , Pessoa de Meia-Idade , Adulto , Sequenciamento do Exoma , Sistema de Registros , Nefrolitíase/genética , Nefrolitíase/epidemiologia , Nefrolitíase/etiologiaRESUMO
BACKGROUND: Three types of primary hyperoxaluria (PH) are recognized. However, data on PH type 2 (PH2), caused by defects in the GRHPR gene, are limited. METHODS: We reviewed the medical records of patients < 18 years of age with genetically-proven PH2 from seven centres across India to identify the age of onset, patterns of clinical presentation, short-term outcomes and genetic profile, and to determine if genotype-phenotype correlation exists. RESULTS: We report 20 patients (all with nephrolithiasis or nephrocalcinosis) diagnosed to have PH2 at a median (IQR) age of 21.5 (7, 60) months. Consanguinity and family history of kidney stones were elicited in nine (45%) and eight (40%) patients, respectively. The median (IQR) serum creatinine at PH2 diagnosis was 0.45 (0.29, 0.56) mg/dL with the corresponding estimated glomerular filtration rate being 83 (60, 96) mL/1.73 m2/min. A mutational hotspot (c.494 G > A), rare in Caucasians, was identified in 12 (60%) patients. An intronic splice site variant (c.735-1G > A) was noted in five (25%) patients. Four (20%) patients required surgical intervention for stone removal. Major adverse kidney events (mortality or chronic kidney disease (CKD) stages 3-5) were noted in six (30%) patients at a median (IQR) follow-up of 12 (6, 27) months. Risk factors for CKD progression and genotype-phenotype correlation could not be established. CONCLUSIONS: PH2 should no longer be considered an innocuous disease, but rather a potentially aggressive disease with early age of presentation, and possible rapid progression to CKD stages 3-5 in childhood in some patients. A mutational hotspot (c.494 G > A variant) was identified in 60% of cases, but needs further exploration to decipher the genotype-phenotype correlation.
Assuntos
Hiperoxalúria Primária , Nefrolitíase , Insuficiência Renal Crônica , Criança , Humanos , Lactente , Perfil Genético , Hiperoxalúria Primária/complicações , Hiperoxalúria Primária/diagnóstico , Hiperoxalúria Primária/genética , Nefrolitíase/genéticaRESUMO
Infantile hypercalcemia type 1 (HCINF1), formerly known as Lightwood syndrome, is a subtype of hypercalcemia caused by loss-of-function biallelic mutations in the vitamin D catabolic enzyme, CYP24A1, which 24-hydroxylates the hormone 1,25-(OH)2D3. This short review focuses on the main features of the HCINF1 disease; emerging knowledge of the structure and function of the cytochrome P450, CYP24A1 and the location of inactivating mutations; the development of a rapid LC-MS/MS-based laboratory test for defective 24-hydroxylation; and future implications for bioanalytical assay and treatment of all types of vitamin D-related hypercalcemic conditions.
Assuntos
Hipercalcemia , Mutação , Nefrocalcinose , Nefrolitíase , Vitamina D3 24-Hidroxilase , Humanos , Hipercalcemia/genética , Hipercalcemia/diagnóstico , Vitamina D3 24-Hidroxilase/genética , Nefrocalcinose/genética , Nefrocalcinose/diagnóstico , Nefrocalcinose/etiologia , Nefrolitíase/genética , Nefrolitíase/etiologia , Vitamina D/metabolismoRESUMO
BACKGROUND: Primary hyperoxaluria type 1 (PH1) is characterized by increased endogenous oxalate production and deposition as calcium oxalate crystals. The main manifestations are nephrocalcinosis/nephrolithiasis, causing impaired kidney function. We aimed to evaluate the clinical characteristics and overall outcomes of paediatric PH1 patients in Turkey. METHODS: This is a nationwide, multicentre, retrospective study evaluating all available paediatric PH1 patients from 15 different paediatric nephrology centres in Turkey. Detailed patient data was collected which included demographic, clinical and laboratory features. Patients were classified according to their age and characteristics at presentation: patients presenting in the first year of life with nephrocalcinosis/nephrolithiasis (infantile oxalosis, Group 1), cases with recurrent nephrolithiasis diagnosed during childhood (childhood-onset PH1, Group 2), and asymptomatic children diagnosed with family screening (Group 3). RESULTS: Forty-eight patients had a mutation consistent with PH1. The most common mutation was c.971_972delTG (25%). Infantile oxalosis patients had more advanced chronic kidney disease (CKD) or kidney failure necessitating dialysis (76.9% vs. 45.5%). These patients had much worse clinical course and mortality rates seemed to be higher (23.1% vs. 13.6%). Patients with fatal outcomes were the ones with significant comorbidities, especially with cardiovascular involvement. Patients in Group 3 were followed with better outcomes, with no kidney failure or mortality. CONCLUSION: PH1 is not an isolated kidney disease but a systemic disease. Family screening helps to preserve kidney function and prevent systemic complications. Despite all efforts made with traditional treatment methods including transplantation, our results show devastating outcomes or mortality.
Assuntos
Hiperoxalúria Primária , Hiperoxalúria , Falência Renal Crônica , Nefrocalcinose , Nefrolitíase , Insuficiência Renal , Humanos , Criança , Nefrocalcinose/diagnóstico , Nefrocalcinose/epidemiologia , Nefrocalcinose/etiologia , Estudos Retrospectivos , Falência Renal Crônica/complicações , Diálise Renal/efeitos adversos , Hiperoxalúria Primária/complicações , Hiperoxalúria Primária/diagnóstico , Hiperoxalúria Primária/genética , Nefrolitíase/complicações , Nefrolitíase/diagnóstico , Nefrolitíase/genética , Hiperoxalúria/complicaçõesRESUMO
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.
Assuntos
Canais de Cloreto , Doença de Dent , Monoéster Fosfórico Hidrolases , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , China/epidemiologia , Canais de Cloreto/genética , Doença de Dent/genética , Doença de Dent/diagnóstico , População do Leste Asiático , Doenças Genéticas Ligadas ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/diagnóstico , Testes Genéticos , Glomerulosclerose Segmentar e Focal/genética , Hipercalciúria/genética , Rim/patologia , Mutação , Mutação de Sentido Incorreto , Nefrocalcinose/genética , Nefrolitíase/genética , Monoéster Fosfórico Hidrolases/genética , Proteinúria/genética , Estudos RetrospectivosRESUMO
Sarcoidosis is a systemic inflammatory disorder characterized by granuloma formation in various organs. It has been associated with nephrolithiasis. The vitamin K epoxide reductase complex subunit 1 (VKORC1) gene, which plays a crucial role in vitamin K metabolism, has been implicated in the activation of proteins associated with calcification, including in the forming of nephrolithiasis. This study aimed to investigate the VKORC1 C1173T polymorphism (rs9934438) in a Dutch sarcoidosis cohort, comparing individuals with and without a history of nephrolithiasis. Retrospectively, 424 patients with sarcoidosis were divided into three groups: those with a history of nephrolithiasis (Group I: n = 23), those with hypercalcemia without nephrolithiasis (Group II: n = 38), and those without nephrolithiasis or hypercalcemia (Group III: n = 363). Of the 424 sarcoidosis patients studied, 5.4% had a history of nephrolithiasis (Group I), only two of whom possessed no VKORC1 polymorphisms (OR = 7.73; 95% CI 1.79-33.4; p = 0.001). The presence of a VKORC1 C1173T variant allele was found to be a substantial risk factor for the development of nephrolithiasis in sarcoidosis patients. This study provides novel insights into the genetic basis of nephrolithiasis in sarcoidosis patients, identifying VKORC1 C1173T as a potential contributor. Further research is warranted to elucidate the precise mechanisms and explore potential therapeutic interventions based on these genetic findings.
Assuntos
Nefrolitíase , Polimorfismo de Nucleotídeo Único , Sarcoidose , Vitamina K Epóxido Redutases , Humanos , Feminino , Vitamina K Epóxido Redutases/genética , Masculino , Sarcoidose/genética , Sarcoidose/complicações , Pessoa de Meia-Idade , Nefrolitíase/genética , Fatores de Risco , Adulto , Predisposição Genética para Doença , Estudos Retrospectivos , Idoso , AlelosRESUMO
In calcium nephrolithiasis (CaNL), most calcium kidney stones are identified as calcium oxalate (CaOx) with variable amounts of calcium phosphate (CaP), where CaP is found as the core component. The nucleation of CaP could be the first step of CaP+CaOx (mixed) stone formation. High urinary supersaturation of CaP due to hypercalciuria and an elevated urine pH have been described as the two main factors in the nucleation of CaP crystals. Our previous in vivo findings (in mice) show that transient receptor potential canonical type 3 (TRPC3)-mediated Ca2+ entry triggers a transepithelial Ca2+ flux to regulate proximal tubular (PT) luminal [Ca2+], and TRPC3-knockout (KO; -/-) mice exhibited moderate hypercalciuria and microcrystal formation at the loop of Henle (LOH). Therefore, we utilized TRPC3 KO mice and exposed them to both hypercalciuric [2% calcium gluconate (CaG) treatment] and alkalineuric conditions [0.08% acetazolamide (ACZ) treatment] to generate a CaNL phenotype. Our results revealed a significant CaP and mixed crystal formation in those treated KO mice (KOT) compared to their WT counterparts (WTT). Importantly, prolonged exposure to CaG and ACZ resulted in a further increase in crystal size for both treated groups (WTT and KOT), but the KOT mice crystal sizes were markedly larger. Moreover, kidney tissue sections of the KOT mice displayed a greater CaP and mixed microcrystal formation than the kidney sections of the WTT group, specifically in the outer and inner medullary and calyceal region; thus, a higher degree of calcifications and mixed calcium lithiasis in the kidneys of the KOT group was displayed. In our effort to find the Ca2+ signaling pathophysiology of PT cells, we found that PT cells from both treated groups (WTT and KOT) elicited a larger Ca2+ entry compared to the WT counterparts because of significant inhibition by the store-operated Ca2+ entry (SOCE) inhibitor, Pyr6. In the presence of both SOCE (Pyr6) and ROCE (receptor-operated Ca2+ entry) inhibitors (Pyr10), Ca2+ entry by WTT cells was moderately inhibited, suggesting that the Ca2+ and pH levels exerted sensitivity changes in response to ROCE and SOCE. An assessment of the gene expression profiles in the PT cells of WTT and KOT mice revealed a safeguarding effect of TRPC3 against detrimental processes (calcification, fibrosis, inflammation, and apoptosis) in the presence of higher pH and hypercalciuric conditions in mice. Together, these findings show that compromise in both the ROCE and SOCE mechanisms in the absence of TRPC3 under hypercalciuric plus higher tubular pH conditions results in higher CaP and mixed crystal formation and that TRPC3 is protective against those adverse effects.
Assuntos
Oxalato de Cálcio , Hipercalciúria , Cálculos Renais , Camundongos Knockout , Animais , Hipercalciúria/metabolismo , Hipercalciúria/genética , Concentração de Íons de Hidrogênio , Camundongos , Oxalato de Cálcio/metabolismo , Cálculos Renais/metabolismo , Cálculos Renais/etiologia , Cálculos Renais/patologia , Fosfatos de Cálcio/metabolismo , Nefrolitíase/metabolismo , Nefrolitíase/genética , Nefrolitíase/patologia , Cálcio/metabolismo , Canais de Cátion TRPC/metabolismo , Canais de Cátion TRPC/genética , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Masculino , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Acetazolamida/farmacologiaRESUMO
The clinical presentation, treatment, and follow-up of two boys with type 1 Dent disease who exhibited a Bartter-like phenotype were retropectively analysed. The related literature of pediatric patients with type 1 Dent disease who had hypokalemia and metabolic alkalosis was screened through databases such as PubMed, CNKI, and Wanfang until February 1, 2024, and common features among these patients were summarized through literature review. A total of 7 literatures were included, and 9 children were included in the analysis. All patients were male, presenting with significant low molecular weight proteinuria and hypercalciuria. Other prominent characteristic phenotypes included short stature (7/8), hypophosphatemia (8/9), and rickets (6/8). Seven previously reported patients had missense or nonsense mutations, while 2 patients in this study carried possible pathogenic mutations in the CLCN5 gene, c.315+2T>A (p.?) and c.584dupT (p.I196Yfs*6), respectively. Five patients were able to maintain blood potassium levels around 3 mmol/L with oral potassium chloride solution combined with non-steroidal anti-inflammatory drugs (ibuprofen or indomethacin). The follow-up showed that 2 patients developed chronic kidney disease stage 4 and stage 3 at the age of 13 and 21 years, respectively. The phenotypic overlap between Dent disease and Batter syndrome is considerable,with the distinguishing feature being the presence of significant low molecular weight proteinuria. Patients with type 1 Dent disease presenting with the Bartter-like phenotype have a high prevalence of short stature, hypophosphatemia, and rickets. Non-steroidal anti-inflammatory drugs can be used to correct hypokalemia in patients under periodic renal function assessment.
Assuntos
Doenças Genéticas Ligadas ao Cromossomo X , Nefrolitíase , Criança , Humanos , Masculino , Síndrome de Bartter/genética , Síndrome de Bartter/diagnóstico , Canais de Cloreto/genética , Doenças Genéticas Ligadas ao Cromossomo X/diagnóstico , Doenças Genéticas Ligadas ao Cromossomo X/genética , Hipercalciúria/diagnóstico , Hipercalciúria/genética , Hipopotassemia/diagnóstico , Hipopotassemia/genética , Hipofosfatemia/diagnóstico , Hipofosfatemia/genética , Mutação , Nefrolitíase/diagnóstico , Nefrolitíase/genética , Fenótipo , Proteinúria/diagnóstico , Proteinúria/genética , Raquitismo/diagnósticoRESUMO
Dent disease 1 (DD1) is a rare X-linked renal proximal tubulopathy characterized by low molecular weight proteinuria and variable degree of hypercalciuria, nephrocalcinosis and/or nephrolithiasis, progressing to chronic kidney disease. Although mutations in the electrogenic Cl-/H+ antiporter ClC-5, which impair endocytic uptake in proximal tubule cells, cause the disease, there is poor genotype-phenotype correlation and their contribution to proximal tubule dysfunction remains unclear. To further discover the mechanisms linking ClC-5 loss-of-function to proximal tubule dysfunction, we have generated novel DD1 cellular models depleted of ClC-5 and carrying ClC-5 mutants p.(Val523del), p.(Glu527Asp) and p.(Ile524Lys) using the human proximal tubule-derived RPTEC/TERT1 cell line. Our DD1 cellular models exhibit impaired albumin endocytosis, increased substrate adhesion and decreased collective migration, correlating with a less differentiated epithelial phenotype. Despite sharing functional features, these DD1 cell models exhibit different gene expression profiles, being p.(Val523del) ClC-5 the mutation showing the largest differences. Gene set enrichment analysis pointed to kidney development, anion homeostasis, organic acid transport, extracellular matrix organization and cell-migration biological processes as the most likely involved in DD1 pathophysiology. In conclusion, our results revealed the pathways linking ClC-5 mutations with tubular dysfunction and, importantly, provide new cellular models to further study DD1 pathophysiology.
Assuntos
Canais de Cloreto/genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/metabolismo , Nefrolitíase/genética , Nefrolitíase/metabolismo , Animais , Fenômenos Biológicos , Linhagem Celular , Canais de Cloreto/metabolismo , Doença de Dent/genética , Endocitose/fisiologia , Estudos de Associação Genética , Doenças Genéticas Ligadas ao Cromossomo X/fisiopatologia , Humanos , Hipercalciúria/genética , Túbulos Renais Proximais/metabolismo , Mutação , Nefrocalcinose/genética , Nefrolitíase/fisiopatologia , Proteinúria/genéticaRESUMO
PURPOSE: Nephrolithiasis (NL) affects 1 in 11 individuals worldwide, leading to significant patient morbidity. NL is associated with nephrocalcinosis (NC), a risk factor for chronic kidney disease. Causative genetic variants are detected in 11% to 28% of NL and/or NC, suggesting that additional NL/NC-associated genetic loci await discovery. Therefore, we employed genomic approaches to discover novel genetic forms of NL/NC. METHODS: Exome sequencing and directed sequencing of the OXGR1 locus were performed in a worldwide NL/NC cohort. Putatively deleterious, rare OXGR1 variants were functionally characterized. RESULTS: Exome sequencing revealed a heterozygous OXGR1 missense variant (c.371T>G, p.L124R) cosegregating with calcium oxalate NL and/or NC disease in an autosomal dominant inheritance pattern within a multigenerational family with 5 affected individuals. OXGR1 encodes 2-oxoglutarate (α-ketoglutarate [AKG]) receptor 1 in the distal nephron. In response to its ligand AKG, OXGR1 stimulates the chloride-bicarbonate exchanger, pendrin, which also regulates transepithelial calcium transport in cortical connecting tubules. Strong amino acid conservation in orthologs and paralogs, severe in silico prediction scores, and extreme rarity in exome population databases suggested that the variant was deleterious. Interrogation of the OXGR1 locus in 1107 additional NL/NC families identified 5 additional deleterious dominant variants in 5 families with calcium oxalate NL/NC. Rare, potentially deleterious OXGR1 variants were enriched in patients with NL/NC compared with Exome Aggregation Consortium controls (χ2 = 7.117, P = .0076). Wild-type OXGR1-expressing Xenopus oocytes exhibited AKG-responsive Ca2+ uptake. Of 5 NL/NC-associated missense variants, 5 revealed impaired AKG-dependent Ca2+ uptake, demonstrating loss of function. CONCLUSION: Rare, dominant loss-of-function OXGR1 variants are associated with recurrent calcium oxalate NL/NC disease.
Assuntos
Nefrolitíase , Receptores Purinérgicos P2 , Humanos , Oxalato de Cálcio , Nefrolitíase/genética , Mutação de Sentido Incorreto/genética , Transportadores de Sulfato/genética , Receptores Purinérgicos P2/genética , Receptores Purinérgicos P2/metabolismoRESUMO
BACKGROUND: Diagnosing genetic kidney disease has become more accessible with low-cost, rapid genetic testing. The study objectives were to determine genetic testing diagnostic yield and examine predictors of genetic diagnosis in children with nephrolithiasis/nephrocalcinosis (NL/NC). METHODS: This retrospective multicenter cross-sectional study was conducted on children ≤ 21 years old with NL/NC from pediatric nephrology/urology centers that underwent the Invitae Nephrolithiasis Panel 1/1/2019-9/30/2021. The diagnostic yield of the genetic panel was calculated. Bivariate and multiple logistic regression were performed to assess for predictors of positive genetic testing. RESULTS: One hundred and thirteen children (83 NL, 30 NC) from 7 centers were included. Genetic testing was positive in 32% overall (29% NL, 40% NC) with definite diagnoses (had pathogenic variants alone) made in 11.5%, probable diagnoses (carried a combination of pathogenic variants and variants of uncertain significance (VUS) in the same gene) made in 5.4%, and possible diagnoses (had VUS alone) made in 15.0%. Variants were found in 28 genes (most commonly HOGA1 in NL, SLC34A3 in NC) and 20 different conditions were identified. Compared to NL, those with NC were younger and had a higher proportion with developmental delay, hypercalcemia, low serum bicarbonate, hypophosphatemia, and chronic kidney disease. In multivariate analysis, low serum bicarbonate was associated with increased odds of genetic diagnosis (ß 2.2, OR 8.7, 95% CI 1.4-54.7, p = 0.02). CONCLUSIONS: Genetic testing was high-yield with definite, probable, or possible explanatory variants found in up to one-third of children with NL/NC and shows promise to improve clinical practice. A higher resolution version of the Graphical abstract is available as Supplementary information.
Assuntos
Cálculos Renais , Nefrocalcinose , Nefrolitíase , Criança , Humanos , Adulto Jovem , Adulto , Nefrocalcinose/diagnóstico , Nefrocalcinose/genética , Bicarbonatos , Estudos Transversais , Nefrolitíase/diagnóstico , Nefrolitíase/genética , Cálculos Renais/genética , Testes GenéticosRESUMO
BACKGROUND: Primary hyperoxalurias (PHs) constitute rare disorders resulting in abnormal glyoxalate metabolism. PH-associated phenotypes range from progressive nephrocalcinosis and/or recurrent urolithiasis to early kidney failure. METHODS: A retrospective study was conducted for patients with confirmed PH diagnoses from three tertiary centers in Saudi Arabia. Detailed clinical molecular diagnosis was performed for 25 affected individuals. Whole exome sequencing (WES)-based molecular diagnosis was performed for all affected individuals. RESULTS: The male:female ratio was 52% male (n = 13) and 48% female (n = 12), and consanguinity was present in 88%. Nephrolithiasis and/or nephrocalcinosis were present in all patients. Kidney stones were present in 72%, nephrocalcinosis in 60%, hematuria in 32%, proteinuria in 16%, abdominal pain in 36%, developmental delay in 8%, and chronic kidney disease stage 5 (CKD stage 5) was observed in 28% of the patients. The most common PH disorder was type I caused by variants in the AGXT gene, accounting for 56%. The GRHPR gene variants were identified in 4 patients, 16% of the total cases. Seven patients did not reveal any associated variants. Missense variants were the most commonly observed variants (48%), followed by frame-shift duplication variants (28%). CONCLUSIONS: Characterization of the genetic and clinical aspects of PH in this unique population provides direction for improved patient management and further research. A higher resolution version of the Graphical abstract is available as Supplementary information.
Assuntos
Hiperoxalúria Primária , Nefrocalcinose , Nefrolitíase , Masculino , Humanos , Feminino , Nefrocalcinose/epidemiologia , Nefrocalcinose/genética , Nefrocalcinose/diagnóstico , Hiperoxalúria Primária/complicações , Hiperoxalúria Primária/diagnóstico , Hiperoxalúria Primária/epidemiologia , Estudos Retrospectivos , Arábia Saudita/epidemiologia , Nefrolitíase/genéticaRESUMO
BACKGROUND: Nephrolithiasis (NL) is a complex multifactorial disease affecting up to 10%-20% of the human population and causing a significant burden on public health systems worldwide. It results from a combination of environmental and genetic factors. Hyperoxaluria is a major risk factor for NL. METHODS: We used a whole exome-based approach in a patient with calcium oxalate NL. The effects of the mutation were characterised using cell culture and in silico analyses. RESULTS: We identified a rare heterozygous missense mutation (c.1519C>T/p.R507W) in the SLC26A6 gene that encodes a secretory oxalate transporter. This mutation cosegregated with hyperoxaluria in the family. In vitro characterisation of mutant SLC26A6 demonstrated that Cl--dependent oxalate transport was dramatically reduced because the mutation affects both SLC26A6 transport activity and membrane surface expression. Cotransfection studies demonstrated strong dominant-negative effects of the mutant on the wild-type protein indicating that the phenotype of patients heterozygous for this mutation may be more severe than predicted by haploinsufficiency alone. CONCLUSION: Our study is in line with previous observations made in the mouse showing that SLC26A6 inactivation can cause inherited enteric hyperoxaluria with calcium oxalate NL. Consistent with an enteric form of hyperoxaluria, we observed a beneficial effect of increasing calcium in the patient's diet to reduce urinary oxalate excretion.
Assuntos
Antiporters , Hiperoxalúria , Nefrolitíase , Transportadores de Sulfato , Humanos , Antiporters/genética , Cálcio/metabolismo , Oxalato de Cálcio/metabolismo , Hiperoxalúria/complicações , Hiperoxalúria/genética , Mutação , Nefrolitíase/genética , Nefrolitíase/complicações , Nefrolitíase/metabolismo , Oxalatos/metabolismo , Transportadores de Sulfato/genéticaRESUMO
Serum phosphate concentration is regulated by renal phosphate reabsorption and mediated by sodium-phosphate cotransporters. Germline mutations in genes encoding these cotransporters have been associated with clinical phenotypes, variably characterized by hyperphosphaturia, hypophosphatemia, recurrent kidney stones, skeletal demineralization, and early onset osteoporosis. We reported a 33-year-old male patient presenting a history of recurrent nephrolithiasis and early onset osteopenia in the lumbar spine and femur. He was tested, through next generation sequencing (NGS), by using a customized multigenic panel containing 33 genes, whose mutations are known to be responsible for the development of congenital parathyroid diseases. Two further genes, SLC34A1 and SLC34A3, encoding two sodium-phosphate cotransporters, were additionally tested. A novel germline heterozygous mutation was identified in the SLC34A1 gene, c.1627G>T (p.Gly543Cys), currently not reported in databases of human gene mutations and scientific literature. SLC34A1 germline heterozygous mutations have been associated with the autosomal dominant hypophosphatemic nephrolithiasis/osteoporosis type 1 (NPHLOP1). Consistently, alongside the clinical features of NPHLOP1, our patient experienced recurrent nephrolithiasis and lumbar and femoral osteopenia at a young age. Genetic screening for the p.Gly453Cys variant and the clinical characterization of his first-degree relatives associated the presence of the variant in one younger brother, presenting renal colic and microlithiasis, suggesting p.Gly453Cys is possibly associated with renal altered function in the NPHLOP1 phenotype.
Assuntos
Raquitismo Hipofosfatêmico Familiar , Nefrolitíase , Osteoporose , Humanos , Masculino , Adulto , Nefrolitíase/complicações , Nefrolitíase/genética , Raquitismo Hipofosfatêmico Familiar/genética , Mutação , Fosfatos/metabolismo , Proteínas Cotransportadoras de Sódio-Fosfato/genética , Sódio , Proteínas Cotransportadoras de Sódio-Fosfato Tipo IIaRESUMO
OBJECTIVE: Hereditary factors are the main cause of pediatric nephrolithiasis (NL)/nephrocalcinosis (NC). We summarized the genotype-phenotype correlation of hereditary NL/NC in our center, to evaluate the role of genetic testing in early diagnosis. METHODS: The clinical data of 32 NL/NC cases, which were suspected to have an inherited basis, were retrospectively analyzed from May 2017 to August 2020. The trio-whole exome sequencing was used as the main approach for genetic testing, variants were confirmed by Sanger sequencing, and pathogenicity analysis according to protein function was predicted with custom-developed software. RESULTS: Causative monogenic mutations were detected in 24 of 32 NL/NC patients, and copy number variation was detected in one patient. A summary of manifestations in patients with inherited diseases revealed a significant degree of growth retardation, increased urinary excretion of the low-molecular weight protein, hypercalciuria, electrolyte imbalances, and young age of onset to be common in heredity disease. In addition, some patients had abnormal renal function (3 ppm 25). The most frequent pathology identified was distal renal tubular acidosis (with inclusion of SLC4A1, ATP6V1B1, and ATP6VOA4 genes), followed by Dent disease (CLCN5 and OCRL1 genes), primary hyperoxaluria (PH) (AGXT and HOGA1 genes) and Kabuki syndrome (KMT2D gene), which was more likely to present as NC or recurrent stone and having a higher correlation with a specific biochemical phenotype and extrarenal phenotype. CONCLUSION: The etiology of NL/NC is heterogeneous. This study explored in depth the relationship between phenotype and genotype in 32 patients, and confirmed that genetic testing and clinical phenotype evaluation enable the precision medicine approach to treating patients.
Assuntos
Nefrocalcinose , Nefrolitíase , Pediatria , ATPases Vacuolares Próton-Translocadoras , Criança , Variações do Número de Cópias de DNA , Testes Genéticos , Humanos , Mutação , Nefrocalcinose/genética , Nefrolitíase/diagnóstico , Nefrolitíase/genética , Medicina de Precisão , Estudos Retrospectivos , ATPases Vacuolares Próton-Translocadoras/genéticaRESUMO
Trefoil Factor 1 (TFF1) is considered to be able to inhibit the formation of kidney stone. However, genetic variants in TFF1 and corresponding function in kidney stone development are still not well studied. In this study, the discovery set including 230 cases and 250 controls was used to analyze the association between seven tagSNPs of TFF1 gene and the nephrolithiasis risk. Further evaluation was confirmed by the validation set comprising 307 cases and 461 controls. The consequences of the two-stage case-control study indicated that individuals with the rs3761376 A allele have significantly increased nephrolithiasis risk than those with the GG genotypes [adjusted odds ratio (OR) = 1.35, 95% confidence interval (CI) = 1.05-1.73]. Moreover, we also carried out a stratified analysis and found the increased nephrolithiasis risks at A allele among males, overweight individuals, no hypertensive individuals, nondiabetic individuals, smokers, and drinkers. In the following functional experiments, the notably lower expression of TFF1 was exhibited by the vectors carrying A allele compared with those carrying G allele in both luciferase (P = 0.022) and expression vectors (P = 0.041). In addition to tissue detection, we confirmed a significant inverse association of rs3761376 G > A and TFF1 gene expression (P < 0.001). These results suggest that TFF1 rs3761376 may serve as a potential biomarker to predict the risk of nephrolithiasis.
Assuntos
Cálculos Renais , Nefrolitíase , Fator Trefoil-1 , Estudos de Casos e Controles , China , Humanos , Cálculos Renais/genética , Masculino , Nefrolitíase/genética , Polimorfismo de Nucleotídeo Único/genética , Fator Trefoil-1/genéticaRESUMO
CYP24A1 is an enzyme that inactivates vitamin D and encodes vitamin D 24-hydroxylase. Mutations in this enzyme have been linked with idiopathic infantile hypercalcemia, nephrolithiasis, and nephrocalcinosis. Genetic testing for this mutation should be considered in the presence of calciuria, elevated serum calcium, elevated 1,25- dihydroxyvitamin D, and suppressed parathyroid hormone. We present a previously healthy eight-month-old male infant with macrohematuria, hypercalciuria (6 mg/kg/24 h), albuminuria (54 mg/24 h) and left-sided nephrolithiasis found on urinary tract ultrasound. The values of alpha 1 microglobulin, parathyroid hormone, vitamin D, serum electrolytes, amino acids, glycols, oxalates and citrates in urine, as well as coagulation tests were normal. Genetic testing excluded suspected Dent's disease but confirmed heterozygous missense variant CYP24A1 c.469C>T, p.(Arg157Trp) classified as polymorphism. He was treated with hydrochlorothiazide and potassium citrate. Children presenting with hypercalcemia, hypercalciuria and nephrolithiasis should be tested because of the importance of recognition, genetic diagnosis and proper treatment of CYP24A1 mutations that can present with a wide range of phenotypic presentations, from asymptomatic to chronic renal disease.
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Hipercalcemia , Nefrocalcinose , Nefrolitíase , Criança , Humanos , Hipercalcemia/complicações , Hipercalcemia/diagnóstico , Hipercalcemia/genética , Hipercalciúria/complicações , Hipercalciúria/diagnóstico , Hipercalciúria/genética , Lactente , Masculino , Nefrocalcinose/diagnóstico , Nefrocalcinose/genética , Nefrolitíase/complicações , Nefrolitíase/genética , Vitamina D3 24-Hidroxilase/genéticaRESUMO
Dent disease 1 (DD1) is caused by mutations in the CLCN5 gene encoding a voltage-gated electrogenic nCl-/H+ exchanger ClC-5. Using ion-selective microelectrodes and Xenopus oocytes, here we studied Cl-/H+ coupling properties of WT ClC-5 and four DD1-associated variants (S244L, R345W, Q629*, and T657S), along with trafficking and localization of ClC-5. WT ClC-5 had a 2Cl-/H+ exchange ratio at a Vh of +40 mV with a [Cl-]out of 104 mm, but the transport direction did not reverse with a [Cl-]out of 5 mm, indicating that ClC-5-mediated exchange of two Cl- out for one H+ in is not permissible. We hypothesized that ClC-5 and H+-ATPase are functionally coupled during H+-ATPase-mediated endosomal acidification, crucial for ClC-5 activation by depolarizing endosomes. ClC-5 transport that provides three net negative charges appeared self-inhibitory because of ClC-5's voltage-gated properties, but shunt conductance facilitated further H+-ATPase-mediated endosomal acidification. Thus, an on-and-off "burst" of ClC-5 activity was crucial for preventing Cl- exit from endosomes. The subcellular distribution of the ClC-5:S244L variant was comparable with that of WT ClC-5, but the variant had a much slower Cl- and H+ transport and displayed an altered stoichiometry of 1.6:1. The ClC-5:R345W variant exhibited slightly higher Cl-/H+ transport than ClC-5:S244L, but co-localized with early endosomes, suggesting decreased ClC-5:R345W membrane trafficking is perhaps in a fully functional form. The truncated ClC-5:Q629* variant displayed the lowest Cl-/H+ exchange and was retained in the endoplasmic reticulum and cis-Golgi, but not in early endosomes, suggesting the nonsense mutation affects ClC-5 maturation and trafficking.
Assuntos
Canais de Cloreto/genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Nefrolitíase/genética , Mutação Puntual , Animais , Linhagem Celular , Canais de Cloreto/análise , Canais de Cloreto/metabolismo , Cloretos/metabolismo , Endossomos/genética , Endossomos/metabolismo , Doenças Genéticas Ligadas ao Cromossomo X/metabolismo , Humanos , Hidrogênio/metabolismo , Transporte de Íons , Nefrolitíase/metabolismo , Transporte Proteico , XenopusRESUMO
BACKGROUND: Distal renal tubular acidosis (dRTA) is characterized by an impairment of urinary acidification resulting in metabolic acidosis, hypokalemia, and inappropriately elevated urine pH. If not treated, this chronic condition eventually leads to nephrocalcinosis, nephrolithiasis, impaired renal function, and bone demineralization. dRTA is a well-defined entity that can be diagnosed by genetic testing of 5 genes known to be disease-causative. Incomplete dRTA (idRTA) is defined as impaired urinary acidification that does not lead to overt metabolic acidosis and therefore can be diagnosed if patients fail to adequately acidify urine after an ammonium chloride (NH4Cl) challenge or furosemide and fludrocortisone test. It is still uncertain whether idRTA represents a distinct entity or is part of the dRTA spectrum and whether it is caused by mutations in the same genes of overt dRTA. METHODS: In this cross-sectional study, we investigated a group of 22 stone formers whose clinical features were suspicious of idRTA. They underwent an NH4Cl challenge and were found to have impaired urinary acidification ability. These patients were then analyzed by genetic testing with sequencing of 5 genes: SLC4A1, ATP6V1B1, ATP6V0A4, FOXI1, and WDR72. RESULTS: Two unrelated individuals were found to have two different variants in SLC4A1 that had never been described before. CONCLUSIONS: Our results suggest the involvement of other genes or nongenetic tubular dysfunction in the pathogenesis of idRTA in stone formers. However, genetic testing may represent a cost-effective tool to recognize, treat, and prevent complications in these patients.