Pseudouridylation defect due to DKC1 and NOP10 mutations causes nephrotic syndrome with cataracts, hearing impairment, and enterocolitis.

RNA modifications play a fundamental role in cellular function. Pseudouridylation, the most abundant RNA modification, is catalyzed by the H/ACA small ribonucleoprotein (snoRNP) complex that shares four core proteins, dyskerin (DKC1), NOP10, NHP2, and GAR1. Mutations in DKC1, NOP10, or NHP2 cause dyskeratosis congenita (DC), a disorder characterized by telomere attrition. Here, we report a phenotype comprising nephrotic syndrome, cataracts, sensorineural deafness, enterocolitis, and early lethality in two pedigrees: males with DKC1 p.Glu206Lys and two children with homozygous NOP10 p.Thr16Met. Females with heterozygous DKC1 p.Glu206Lys developed cataracts and sensorineural deafness, but nephrotic syndrome in only one case of skewed X-inactivation. We found telomere attrition in both pedigrees, but no mucocutaneous abnormalities suggestive of DC. Both mutations fall at the dyskerin-NOP10 binding interface in a region distinct from those implicated in DC, impair the dyskerin-NOP10 interaction, and disrupt the catalytic pseudouridylation site. Accordingly, we found reduced pseudouridine levels in the ribosomal RNA (rRNA) of the patients. Zebrafish dkc1 mutants recapitulate the human phenotype and show reduced 18S pseudouridylation, ribosomal dysregulation, and a cell-cycle defect in the absence of telomere attrition. We therefore propose that this human disorder is the consequence of defective snoRNP pseudouridylation and ribosomal dysfunction.

Activation of podocyte Notch mediates early Wt1 glomerulopathy.

The Wilms' tumor suppressor gene, WT1, encodes a zinc finger protein that regulates podocyte development and is highly expressed in mature podocytes. Mutations in the WT1 gene are associated with the development of renal failure due to the formation of scar tissue within glomeruli, the mechanisms of which are poorly understood. Here, we used a tamoxifen-based CRE-LoxP system to induce deletion of Wt1 in adult mice to investigate the mechanisms underlying evolution of glomerulosclerosis. Podocyte apoptosis was evident as early as the fourth day post-induction and increased during disease progression, supporting a role for Wt1 in mature podocyte survival. Podocyte Notch activation was evident at disease onset with upregulation of Notch1 and its transcriptional targets, including Nrarp. There was repression of podocyte FoxC2 and upregulation of Hey2 supporting a role for a Wt1/FoxC2/Notch transcriptional network in mature podocyte injury. The expression of cleaved Notch1 and HES1 proteins in podocytes of mutant mice was confirmed in early disease. Furthermore, induction of podocyte HES1 expression was associated with upregulation of genes implicated in epithelial mesenchymal transition, thereby suggesting that HES1 mediates podocyte EMT. Lastly, early pharmacological inhibition of Notch signaling ameliorated glomerular scarring and albuminuria. Thus, loss of Wt1 in mature podocytes modulates podocyte Notch activation, which could mediate early events in WT1-related glomerulosclerosis.

Deregulated expression of autophagy genes; PIK3C3 and RAB7A in COVID-19 patients.

BACKGROUND: The role of autophagy in coronaviruses infection and replication has a lot of debate. Autophagy involves the catalytic breakdown of intracellular components to be subsequently recycled by the lysosome. The aim of the study was to evaluate autophagy genes; PIK3C3 and RAB7A expressions in COVID-19 patients, and identify if PIK3C3 and RAB7A can be used as markers for monitoring COVID-19 patients. METHODS: A case-control study was carried out on 50 patients and 50 healthy controls. Genes expression was performed using quantitative real-time polymerase chain reaction. RESULTS: Compared to controls, PIK3C3 and RAB7A gene expression levels were significantly lower in patients (p < 0.001) with approximately with 9.4 and 2.3 decreased fold in PIK3C3 and RAB7A respectively. The ROC curve of PIK3C3 and RAB7A expressions showed sensitivity of 84 % and 74 % and specificity of 98 % and 78 % respectively. There was a positive correlation between PIK3C3 expression and WBCs, absolute neutrophil count, interleukin-6, D-dimer, and ALT among patients and between RAB7A expression and WBCs, CRP, IL-6, D-dimer and ALT in patients. CONCLUSIONS: The study showed reduction of PIK3C3 and RAB7A expressions in COVID-19 patients. However, further studies are recommended to clarify their roles in the disease pathogenies as autophagy genes.

Tolloid-like 1 gene variant rs17047200, pretreatment FIB-4, ALBI and PALBI scores as predictors of hepatocellular carcinoma occurrence after directly acting antivirals.

Aim of the study: Identifying persons at increased risk of developing hepatocellular carcinoma (HCC) after exposure to directly acting antivirals (DAAs) is of utmost importance. Our aim was to identify the predictors of de novo HCC occurrence among cirrhotic patients after hepatitis C virus (HCV) treatment using DAAs. Material and methods: 529 cirrhotic patients who initiated treatment for HCV using DAAs were followed up for 2 years from the end of treatment for development of HCC. Pretreatment clinical and laboratory data were assessed as possible predictors for HCC occurrence. Genotyping for tolloid-like 1 gene (TLL1) variant rs17047200 was assessed in all patients who developed HCC and in the matched control group. Results: Pretreatment bilirubin, FIB-4 and platelet-albumin-bilirubin (PALBI) scores were significantly higher among those who developed HCC than those who did not develop HCC during the 2-year follow-up period while hemoglobin level was significantly lower. ROC curve analysis revealed that at a cut-off ≥ 3.07, pretreatment FIB-4 had a sensitivity of 76.5%, and negative predictive value (NPV) of 92%. At a cut-off ≥ -2.5, pretreatment PALBI score had a sensitivity of 82.4%, and NPV of 93.2%. Regarding genotyping for TLL1 rs17047200 there were no statistically significant differences between those who developed HCC during follow-up and the matched control group. Conclusions: TLL1 rs17047200 genotyping is not helpful in predicting HCC occurrence after DAAs. On the other hand, lower pretreatment hemoglobin level and higher pretreatment bilirubin, FIB-4 and PALBI scores are associated with higher risk of HCC development after DAAs.

ASSESSING PREDICTORS OF DIRECTLY ACTING ANTIVIRALS' FAILURE AS A FURTHER STEP TOWARDS MORE EFFICIENT HCV ELIMINATION PROGRAMS: IL28B (IFNL4) GENE POLYMORPHISM HAS NO ROLE WHILE HIGHER ESTIMATED CREATININE CLEARANCE IS A FORGOTTEN FACTOR.

BACKGROUND: Sustained virologic response (SVR) rates after directly acting antivirals (DAAs) for hepatitis C virus (HCV) exceed 95%. This encouraged policymakers to put plans to achieve HCV elimination by 2030. The remaining percentage of non-SVR12 can affect HCV eradication strategies in the real-world especially the compliance of large numbers of treated persons to follow up for assessment of virologic response cannot be guaranteed. OBJECTIVE: We aimed to assess predictors of failure to achieve SVR after receiving sofosbuvir plus NS5A inhibitor as an important step towards achieving better HCV eradication strategies. METHODS: During the period from 1st November 2018 to 1st November 2019, 1581 treatment-naive patients received sofosbuvir plus daclatasvir ± ribavirin at our unit and 10 patients were referred to us with HCV relapse after the same regimens. A total of 163 out of the 1581 patients were lost for follow-up before assessment of virologic response and excluded from the analysis. 20 out of the remaining patients failed to achieve SVR12. Data from the 30 patients with non-SVR12 were included in the case-control analysis. RESULTS: Every unit increase in estimated creatinine clearance using modification of diet in renal disease study (MDRD) score, total bilirubin, and INR was associated with 1.03, 13.92, and 80.08 times greater odds of non-SVR12 (P<0.001, P=0.0016, P=0.02) respectively. The presence of liver cirrhosis on ultrasonography increases the odds by 10.03. (P=0.009). CONCLUSION: Higher MDRD score, INR, total bilirubin, and presence of sonographic features of liver cirrhosis are predictors of failure to achieve SVR12 using sofosbuvir plus NS5A inhibitor.

Preliminary results of targeted sequencing of BRCA1 and BRCA2 in a cohort of breast cancer families: New insight into pathogenic variants in patients and at­risk relatives.

Breast cancer (BC) is the most commonly diagnosed cancer worldwide and a major health concern in Egypt. There is a known association between pathogenic variants identified in breast cancer susceptibility gene (BRCA)1 and 2 and the risk of developing BC. However, the number of studies investigating mutations in BRCA1 and BRCA2 in Egypt remains limited. Thus, the aim of the present study was to investigate the frequency of BRCA1 and BRCA2 variants in patients with BC and their relatives. For this purpose, 11 families (11 patients and 16 relatives) were included in the present study. BRCA1 and BRCA2 variants were investigated using the Ion S5 next­generation sequencer. It was found that pathogenic variants were more frequent in patients with familial BC (FBC) than in those with sporadic BC, with 71% of variants in BRCA2, including the first reported identification of c.9089del, c.5583_5584dup, c.8243G>A and c.7976G>A pathogenic variants in Egyptian patients with BC. Pathogenic variants in relatives were confined to FBC c.1278delA, c.1960_1961del, and c.1224delT, with a higher incidence of variants of uncertain significance (VUS), such as BRCA2 intron 2 c.68­16delT. Of note, two cold spot benign variants, c.3113A>G and c.4837A>G, were repeatedly found (67%) in patients and relatives. In conclusion, to the best of our knowledge, novel pathogenic variants and VUS in Egyptian patients with BC and their high­risk relatives were identified for the first time in the present study. These findings should be integrated with other genomic data concerning Egyptian families and carefully interpreted during genetic counseling.

Mutations in LAMB2 Are Associated With Albuminuria and Optic Nerve Hypoplasia With Hypopituitarism.

CONTEXT: Mutations in LAMB2, encoding the basement membrane protein, laminin ß2, are associated with an autosomal recessive disorder characterized by congenital nephrotic syndrome, ocular abnormalities, and neurodevelopmental delay (Pierson syndrome). CASE DESCRIPTION: This report describes a 12-year-old boy with short stature, visual impairment, and developmental delay who presented with macroscopic hematuria and albuminuria. He had isolated growth hormone deficiency, optic nerve hypoplasia, and a small anterior pituitary with corpus callosum dysgenesis on his cranial magnetic resonance imaging, thereby supporting a diagnosis of optic nerve hypoplasia syndrome. Renal histopathology revealed focal segmental glomerulosclerosis. Using next-generation sequencing on a targeted gene panel for steroid-resistant nephrotic syndrome, compound heterozygous missense mutations were identified in LAMB2 (c.737G>A p.Arg246Gln, c.3982G>C p.Gly1328Arg). Immunohistochemical analysis revealed reduced glomerular laminin ß2 expression compared to control kidney and a thin basement membrane on electron microscopy. Laminin ß2 is expressed during pituitary development and Lamb2-/- mice exhibit stunted growth, abnormal neural retinae, and here we show, abnormal parenchyma of the anterior pituitary gland. CONCLUSION: We propose that patients with genetically undefined optic nerve hypoplasia syndrome should be screened for albuminuria and, if present, screened for mutations in LAMB2.

Avaliação dos preditores da falha dos antivirais de ação direta como mais um passo para programas de eliminação de VHC mais eficiente: o polimorfismo genético IL28B (IFNL4) não tem destaque, enquanto maior liberação estimada do "clearence" de creatinina é um fator esquecido / Assessing predictors of directly acting antivirals' failure as a further step towards more efficient hcv elimination programs: il28b (ifnl4) gene polymorphism has no role while higher estimated creatinine clearance is a forgotten factor

ABSTRACT Background: Sustained virologic response (SVR) rates after directly acting antivirals (DAAs) for hepatitis C virus (HCV) exceed 95%. This encouraged policymakers to put plans to achieve HCV elimination by 2030. The remaining percentage of non-SVR12 can affect HCV eradication strategies in the real-world especially the compliance of large numbers of treated persons to follow up for assessment of virologic response cannot be guaranteed. Objective: We aimed to assess predictors of failure to achieve SVR after receiving sofosbuvir plus NS5A inhibitor as an important step towards achieving better HCV eradication strategies. Methods: During the period from 1st November 2018 to 1st November 2019, 1581 treatment-naive patients received sofosbuvir plus daclatasvir ± ribavirin at our unit and 10 patients were referred to us with HCV relapse after the same regimens. A total of 163 out of the 1581 patients were lost for follow-up before assessment of virologic response and excluded from the analysis. 20 out of the remaining patients failed to achieve SVR12. Data from the 30 patients with non-SVR12 were included in the case-control analysis. Results: Every unit increase in estimated creatinine clearance using modification of diet in renal disease study (MDRD) score, total bilirubin, and INR was associated with 1.03, 13.92, and 80.08 times greater odds of non-SVR12 (P<0.001, P=0.0016, P=0.02) respectively. The presence of liver cirrhosis on ultrasonography increases the odds by 10.03. (P=0.009). Conclusion: Higher MDRD score, INR, total bilirubin, and presence of sonographic features of liver cirrhosis are predictors of failure to achieve SVR12 using sofosbuvir plus NS5A inhibitor.

RESUMO Contexto: As taxas de resposta virológica sustentada (SVR) após ação direta de antivirais (DAAs) para o vírus da hepatite C (VHC) excedem 95%. Isso encorajou os formuladores de políticas a colocar planos para alcançar a eliminação do VHC até 2030. O percentual remanescente de não-respondedores pode afetar as estratégias de erradicação do VHC no mundo real, especialmente a conformidade de um grande número de pessoas tratadas para acompanhamento para avaliação da resposta virológica não pode ser garantida. Objetivo: Nosso objetivo foi avaliar os preditores de não atingir o SVR após receber o inibidor sofosbuvir mais NS5A como um passo importante para alcançar melhores estratégias de erradicação do VHC. Métodos: No período de 1º de novembro de 2018 a 1º de novembro de 2019, 1581 pacientes receberam sofosbuvir mais daclatasvir ± ribavirin em nossa unidade e 10 pacientes foram encaminhados por recaída do VHC após os mesmos regimes. Um total de 163 dos 1581 pacientes foram perdidos para o acompanhamento antes da avaliação da resposta virológica e excluídos da análise. 20 dos demais pacientes não conseguiram a resposta virológica sustentada (SVR12). Os dados de 30 pacientes com não SVR12 foram incluídos na análise caso-controle. Resultados: Cada unidade aumentada no clearence estimado de creatinina usando o escore do estudo Modificação da Dieta em Doença Renal (MDRD), bilirrubina total e INR foram associadas a 1,03, 13,92 e 80,08 vezes maiores chances de não-SVR12 (P<0,001, P=0,0016, P=0,02) respectivamente. A presença de cirrose hepática na ultrassonografia aumenta as chances em 10,03. (P=0,009). Conclusão: Maior escore de MDRD, INR, bilirrubina total e presença de características sonográficas de cirrose hepática são preditores de falha na realização do SVR12 utilizando o inibidor sofosbuvir mais NS5A.