@article {976, title = {Beyond the tubule: pathological variants of , encoding the megalin receptor, result in glomerular loss and early progressive chronic kidney disease.}, journal = {Am J Physiol Renal Physiol}, volume = {319}, year = {2020}, month = {2020 12 01}, pages = {F988-F999}, abstract = {

Pathogenic variants in the gene, encoding the multiligand receptor megalin, cause a rare autosomal recessive syndrome: Donnai-Barrow/Facio-Oculo-Acoustico-Renal (DB/FOAR) syndrome. Because of the rarity of the syndrome, the long-term consequences of the tubulopathy on human renal health have been difficult to ascertain, and the human clinical condition has hitherto been characterized as a benign tubular condition with asymptomatic low-molecular-weight proteinuria. We investigated renal function and morphology in a murine model of DB/FOAR syndrome and in patients with DB/FOAR. We analyzed glomerular filtration rate in mice by FITC-inulin clearance and clinically characterized six families, including nine patients with DB/FOAR and nine family members. Urine samples from patients were analyzed by Western blot analysis and biopsy materials were analyzed by histology. In the mouse model, we used histological methods to assess nephrogenesis and postnatal renal structure and contrast-enhanced magnetic resonance imaging to assess glomerular number. In megalin-deficient mice, we found a lower glomerular filtration rate and an increase in the abundance of injury markers, such as kidney injury molecule-1 and -acetyl-β-d-glucosaminidase. Renal injury was validated in patients, who presented with increased urinary kidney injury molecule-1, classical markers of chronic kidney disease, and glomerular proteinuria early in life. Megalin-deficient mice had normal nephrogenesis, but they had 19\% fewer nephrons in early adulthood and an increased fraction of nephrons with disconnected glomerulotubular junction. In conclusion, megalin dysfunction, as present in DB/FOAR syndrome, confers an increased risk of progression into chronic kidney disease.

}, keywords = {Adolescent, Adult, Animals, Child, Child, Preschool, Female, Genetic Predisposition to Disease, Genetic Variation, Humans, Kidney Glomerulus, Low Density Lipoprotein Receptor-Related Protein-2, Male, Mice, Mice, Knockout, Middle Aged, Renal Insufficiency, Chronic, Young Adult}, issn = {1522-1466}, doi = {10.1152/ajprenal.00295.2020}, author = {Charlton, Jennifer R and Tan, Weizhen and Daouk, Ghaleb and Teot, Lisa and Rosen, Seymour and Bennett, Kevin M and Cwiek, Aleksandra and Nam, Sejin and Emma, Francesco and Jouret, Fran{\c c}ois and Oliveira, Jo{\~a}o Paulo and Tranebj{\ae}rg, Lisbeth and Frykholm, Carina and Mane, Shrikant and Hildebrandt, Friedhelm and Srivastava, Tarak and Storm, Tina and Christensen, Erik Ils{\o} and Nielsen, Rikke} } @article {647, title = {Inherited glomerular diseases in the gilded age of genomic advancements.}, journal = {Pediatr Nephrol}, volume = {35}, year = {2020}, month = {2020 06}, pages = {959-968}, abstract = {

The synchronized advent of high-throughput next-generation sequencing technology and knowledge of the human genome has rendered exponential contributions to our understanding of the pathophysiology of glomerular kidney diseases. A genetic diagnosis can now be made or confirmed in about two-thirds of the suspected inherited glomerular diseases. Next-generation sequencing is adept at identifying single nucleotide variations and small insertions or deletions that constitute majority of the disease-causing mutations. Description of the complete mutation spectrum in syndromic glomerulopathies may require the use of both sequencing and cytogenetic methods to detect large structural DNA variation in addition to single nucleotide changes. The enthusiastic application of genetic and genomic knowledge to inherited glomerular diseases has uncovered anticipated and unforeseen challenges mainly related to the biological interpretation of variants of uncertain significance and the limited benefit on clinical management for the individual patient when a diagnosis is obtained. To attain the ultimate goal of transforming clinical decision-making based on accurate genetic diagnosis using genomic information, these challenges need to be addressed. Till then, the glory of genomic medicine stands the test of time in this gilded age of genomic advancements.

}, keywords = {Adolescent, Age Factors, Branchio-Oto-Renal Syndrome, Child, Female, High-Throughput Nucleotide Sequencing, Humans, Infant, Kidney Failure, Chronic, Male, Middle Aged, Mutation, Pedigree, Polymorphism, Single Nucleotide, Renal Insufficiency, Chronic, Whole Exome Sequencing}, issn = {1432-198X}, doi = {10.1007/s00467-019-04266-y}, author = {Gulati, Ashima and Dahl, Neera and Tufro, Alda} } @article {596, title = {Whole-Exome Sequencing Enables a Precision Medicine Approach for Kidney Transplant Recipients.}, journal = {J Am Soc Nephrol}, volume = {30}, year = {2019}, month = {2019 02}, pages = {201-215}, abstract = {

BACKGROUND: Whole-exome sequencing (WES) finds a CKD-related mutation in approximately 20\% of patients presenting with CKD before 25 years of age. Although provision of a molecular diagnosis could have important implications for clinical management, evidence is lacking on the diagnostic yield and clinical utility of WES for pediatric renal transplant recipients.

METHODS: To determine the diagnostic yield of WES in pediatric kidney transplant recipients, we recruited 104 patients who had received a transplant at Boston Children{\textquoteright}s Hospital from 2007 through 2017, performed WES, and analyzed results for likely deleterious variants in approximately 400 genes known to cause CKD.

RESULTS: By WES, we identified a genetic cause of CKD in 34 out of 104 (32.7\%) transplant recipients. The likelihood of detecting a molecular genetic diagnosis was highest for patients with urinary stone disease (three out of three individuals), followed by renal cystic ciliopathies (seven out of nine individuals), steroid-resistant nephrotic syndrome (nine out of 21 individuals), congenital anomalies of the kidney and urinary tract (ten out of 55 individuals), and chronic glomerulonephritis (one out of seven individuals). WES also yielded a molecular diagnosis for four out of nine individuals with ESRD of unknown etiology. The WES-related molecular genetic diagnosis had implications for clinical care for five patients.

CONCLUSIONS: Nearly one third of pediatric renal transplant recipients had a genetic cause of their kidney disease identified by WES. Knowledge of this genetic information can help guide management of both transplant patients and potential living related donors.

}, keywords = {Adolescent, Boston, Child, Child, Preschool, Cohort Studies, Female, Genetic Predisposition to Disease, Genetic Testing, Graft Rejection, Graft Survival, Hospitals, Pediatric, Humans, Kidney Transplantation, Male, Precision Medicine, Prognosis, Renal Insufficiency, Chronic, Retrospective Studies, Risk Assessment, Severity of Illness Index, Survival Analysis, Transplant Recipients, Treatment Outcome, Whole Exome Sequencing}, issn = {1533-3450}, doi = {10.1681/ASN.2018060575}, author = {Mann, Nina and Braun, Daniela A and Amann, Kassaundra and Tan, Weizhen and Shril, Shirlee and Connaughton, Dervla M and Nakayama, Makiko and Schneider, Ronen and Kitzler, Thomas M and van der Ven, Amelie T and Chen, Jing and Ityel, Hadas and Vivante, Asaf and Majmundar, Amar J and Daga, Ankana and Warejko, Jillian K and Lovric, Svjetlana and Ashraf, Shazia and Jobst-Schwan, Tilman and Widmeier, Eugen and Hugo, Hannah and Mane, Shrikant M and Spaneas, Leslie and Somers, Michael J G and Ferguson, Michael A and Traum, Avram Z and Stein, Deborah R and Baum, Michelle A and Daouk, Ghaleb H and Lifton, Richard P and Manzi, Shannon and Vakili, Khashayar and Kim, Heung Bae and Rodig, Nancy M and Hildebrandt, Friedhelm} } @article {124, title = {Whole exome sequencing identifies causative mutations in the majority of consanguineous or familial cases with childhood-onset increased renal echogenicity.}, journal = {Kidney Int}, volume = {89}, year = {2016}, month = {2016 Feb}, pages = {468-475}, abstract = {

Chronically increased echogenicity on renal ultrasound is a sensitive early finding of chronic kidney disease that can be detected before manifestation of other symptoms. Increased echogenicity, however, is not specific for a certain etiology of chronic kidney disease. Here, we performed whole exome sequencing in 79 consanguineous or familial cases of suspected nephronophthisis in order to determine the underlying molecular disease cause. In 50 cases, there was a causative mutation in a known monogenic disease gene. In 32 of these cases whole exome sequencing confirmed the diagnosis of a nephronophthisis-related ciliopathy. In 8 cases it revealed the diagnosis of a renal tubulopathy. The remaining 10 cases were identified as Alport syndrome (4), autosomal-recessive polycystic kidney disease (2), congenital anomalies of the kidney and urinary tract (3), and APECED syndrome (1). In 5 families, in whom mutations in known monogenic genes were excluded, we applied homozygosity mapping for variant filtering and identified 5 novel candidate genes (RBM48, FAM186B, PIAS1, INCENP, and RCOR1) for renal ciliopathies. Thus, whole exome sequencing allows the detection of the causative mutation in 2/3 of affected individuals, thereby presenting the etiologic diagnosis, and allows identification of novel candidate genes.

}, keywords = {Age of Onset, Cohort Studies, DNA Mutational Analysis, Exome, Humans, Kidney Diseases, Cystic, Renal Insufficiency, Chronic}, issn = {1523-1755}, doi = {10.1038/ki.2015.317}, author = {Braun, Daniela A and Schueler, Markus and Halbritter, Jan and Gee, Heon Yung and Porath, Jonathan D and Lawson, Jennifer A and Airik, Rannar and Shril, Shirlee and Allen, Susan J and Stein, Deborah and Al Kindy, Adila and Beck, Bodo B and Cengiz, Nurcan and Moorani, Khemchand N and Ozaltin, Fatih and Hashmi, Seema and Sayer, John A and Bockenhauer, Detlef and Soliman, Neveen A and Otto, Edgar A and Lifton, Richard P and Hildebrandt, Friedhelm} } @article {306, title = {Recessive mutations in DGKE cause atypical hemolytic-uremic syndrome.}, journal = {Nat Genet}, volume = {45}, year = {2013}, month = {2013 May}, pages = {531-6}, abstract = {

Pathologic thrombosis is a major cause of mortality. Hemolytic-uremic syndrome (HUS) features episodes of small-vessel thrombosis resulting in microangiopathic hemolytic anemia, thrombocytopenia and renal failure. Atypical HUS (aHUS) can result from genetic or autoimmune factors that lead to pathologic complement cascade activation. Using exome sequencing, we identified recessive mutations in DGKE (encoding diacylglycerol kinase ɛ) that co-segregated with aHUS in nine unrelated kindreds, defining a distinctive Mendelian disease. Affected individuals present with aHUS before age 1 year, have persistent hypertension, hematuria and proteinuria (sometimes in the nephrotic range), and develop chronic kidney disease with age. DGKE is found in endothelium, platelets and podocytes. Arachidonic acid-containing diacylglycerols (DAG) activate protein kinase C (PKC), which promotes thrombosis, and DGKE normally inactivates DAG signaling. We infer that loss of DGKE function results in a prothrombotic state. These findings identify a new mechanism of pathologic thrombosis and kidney failure and have immediate implications for treating individuals with aHUS.

}, keywords = {Acute Kidney Injury, Atypical Hemolytic Uremic Syndrome, Child, Child, Preschool, Diacylglycerol Kinase, Exome, Female, Genes, Recessive, Hemolytic-Uremic Syndrome, Humans, Immunoenzyme Techniques, Infant, Male, Molecular Sequence Data, Mutation, Renal Insufficiency, Chronic, Thrombocytopenia, Thrombotic Microangiopathies}, issn = {1546-1718}, doi = {10.1038/ng.2590}, author = {Lemaire, Mathieu and Fremeaux-Bacchi, Veronique and Schaefer, Franz and Choi, Murim and Tang, Wai Ho and Le Quintrec, Moglie and Fakhouri, Fadi and Taque, Sophie and Nobili, Fran{\c c}ois and Martinez, Frank and Ji, Weizhen and Overton, John D and Mane, Shrikant M and N{\"u}rnberg, Gudrun and Altm{\"u}ller, Janine and Thiele, Holger and Morin, Denis and Deschenes, Georges and Baudouin, V{\'e}ronique and Llanas, Brigitte and Collard, Laure and Majid, Mohammed A and Simkova, Eva and N{\"u}rnberg, Peter and Rioux-Leclerc, Nathalie and Moeckel, Gilbert W and Gubler, Marie Claire and Hwa, John and Loirat, Chantal and Lifton, Richard P} }