@article {441, title = {Whole exome sequencing frequently detects a monogenic cause in early onset nephrolithiasis and~nephrocalcinosis.}, journal = {Kidney Int}, volume = {93}, year = {2018}, month = {2018 01}, pages = {204-213}, abstract = {

The incidence of nephrolithiasis continues to rise. Previously, we showed that a monogenic cause could be detected in 11.4\% of individuals with adult-onset nephrolithiasis or nephrocalcinosis and in 16.7-20.8\% of individuals with onset before 18 years of age, using gene panel sequencing of 30 genes known to cause nephrolithiasis/nephrocalcinosis. To overcome the limitations of panel sequencing, we utilized whole exome sequencing in 51 families, who presented before age 25 years with at least one renal stone or with a renal ultrasound finding of nephrocalcinosis to identify the underlying molecular genetic cause of disease. In 15 of 51 families, we detected a monogenic causative mutation by whole exome sequencing. A mutation in seven recessive genes (AGXT, ATP6V1B1, CLDN16, CLDN19, GRHPR, SLC3A1, SLC12A1), in one dominant gene (SLC9A3R1), and in one gene (SLC34A1) with both recessive and dominant inheritance was detected. Seven of the 19 different mutations were not previously described as disease-causing. In one family, a causative mutation in one of 117 genes that may represent phenocopies of nephrolithiasis-causing genes was detected. In nine of 15 families, the genetic diagnosis may have specific implications for stone management and prevention. Several factors that correlated with the higher detection rate in our cohort were younger age at onset of nephrolithiasis/nephrocalcinosis, presence of multiple affected members in a family, and presence of consanguinity. Thus, we established whole exome sequencing as an efficient approach toward a molecular genetic diagnosis in individuals with nephrolithiasis/nephrocalcinosis who manifest before age 25 years.

}, keywords = {Adolescent, Age of Onset, Child, Child, Preschool, Disease Progression, Female, Genetic Association Studies, Genetic Markers, Genetic Predisposition to Disease, Heredity, Humans, Infant, Male, Mutation, Nephrocalcinosis, Nephrolithiasis, Pedigree, Phenotype, Predictive Value of Tests, Prognosis, Risk Factors, Tomography, X-Ray Computed, Ultrasonography, Whole Exome Sequencing, Young Adult}, issn = {1523-1755}, doi = {10.1016/j.kint.2017.06.025}, author = {Daga, Ankana and Majmundar, Amar J and Braun, Daniela A and Gee, Heon Yung and Lawson, Jennifer A and Shril, Shirlee and Jobst-Schwan, Tilman and Vivante, Asaf and Schapiro, David and Tan, Weizhen and Warejko, Jillian K and Widmeier, Eugen and Nelson, Caleb P and Fathy, Hanan M and Gucev, Zoran and Soliman, Neveen A and Hashmi, Seema and Halbritter, Jan and Halty, Margarita and Kari, Jameela A and El-Desoky, Sherif and Ferguson, Michael A and Somers, Michael J G and Traum, Avram Z and Stein, Deborah R and Daouk, Ghaleb H and Rodig, Nancy M and Katz, Avi and Hanna, Christian and Schwaderer, Andrew L and Sayer, John A and Wassner, Ari J and Mane, Shrikant and Lifton, Richard P and Milosevic, Danko and Tasic, Velibor and Baum, Michelle A and Hildebrandt, Friedhelm} } @article {640, title = {Characterization of a New DGKE Intronic Mutation in Genetically Unsolved Cases of Familial Atypical Hemolytic Uremic Syndrome.}, journal = {Clin J Am Soc Nephrol}, volume = {10}, year = {2015}, month = {2015 Jun 05}, pages = {1011-9}, abstract = {

BACKGROUND AND OBJECTIVES: Genetic and acquired abnormalities causing dysregulation of the complement alternative pathway contribute to atypical hemolytic uremic syndrome (aHUS), a rare disorder characterized by thrombocytopenia, nonimmune microangiopathic hemolytic anemia, and acute kidney failure. However, in a substantial proportion of patients the disease-associated alterations are still unknown.

DESIGN, SETTING, PARTICIPANTS, \& MEASUREMENTS: Whole-exome and whole-genome sequencing were performed in two unrelated families with infantile recessive aHUS. Sequencing of cDNA from affected individuals was used to test for the presence of aberrant mRNA species. Expression of mutant diacylglycerol kinase epsilon (DGKE) protein was evaluated with western blotting.

RESULTS: Whole-exome sequencing analysis with conventional variant filtering parameters did not reveal any obvious candidate mutation in the first family. The report of aHUS-associated mutations in DGKE, encoding DGKE, led to re-examination of the noncoding DGKE variants obtained from next-generation sequencing, allowing identification of a novel intronic DGKE mutation (c.888+40A>G) that segregated with disease. Sequencing of cDNA from affected individuals revealed aberrant forms of DGKE mRNA predicted to cause profound abnormalities in the protein catalytic site. By whole-genome sequencing, the same mutation was found in compound heterozygosity with a second nonsense DGKE mutation in all affected siblings of another unrelated family. Homozygous and compound heterozygous patients presented similar clinical features, including aHUS presentation in the first year of life, multiple relapsing episodes, and proteinuria, which are prototypical of DGKE-associated aHUS.

CONCLUSIONS: This is the first report of a mutation located beyond the exon-intron boundaries in aHUS. Intronic mutations such as these are underreported because conventional filtering parameters used to process next-generation sequencing data routinely exclude these regions from downstream analyses in both research and clinical settings. The results suggest that analysis of noncoding regions of aHUS-associated genes coupled with mRNA sequencing might provide a tool to explain genetically unsolved aHUS cases.

}, keywords = {Adolescent, Atypical Hemolytic Uremic Syndrome, Base Sequence, Blotting, Western, Child, Diacylglycerol Kinase, DNA Mutational Analysis, Female, Genetic Association Studies, Genetic Predisposition to Disease, Heterozygote, Homozygote, Humans, Infant, Introns, Male, Molecular Sequence Data, Mutation, Phenotype, Predictive Value of Tests, Risk Factors}, issn = {1555-905X}, doi = {10.2215/CJN.08520814}, author = {Mele, Caterina and Lemaire, Mathieu and Iatropoulos, Paraskevas and Piras, Rossella and Bresin, Elena and Bettoni, Serena and Bick, David and Helbling, Daniel and Veith, Regan and Valoti, Elisabetta and Donadelli, Roberta and Murer, Luisa and Neunh{\"a}userer, Maria and Breno, Matteo and Fremeaux-Bacchi, Veronique and Lifton, Richard and Remuzzi, Giuseppe and Noris, Marina} }