@article {451, title = {Congenital Titinopathy: Comprehensive characterization and pathogenic insights.}, journal = {Ann Neurol}, volume = {83}, year = {2018}, month = {2018 Jun}, pages = {1105-1124}, abstract = {

OBJECTIVE: Comprehensive clinical characterization of congenital titinopathy to facilitate diagnosis and management of this important emerging disorder.

METHODS: Using massively parallel sequencing we identified 30 patients from 27 families with 2 pathogenic nonsense, frameshift and/or splice site TTN mutations in trans. We then undertook a detailed analysis of the clinical, histopathological and imaging features of these patients.

RESULTS: All patients had prenatal or early onset hypotonia and/or congenital contractures. None had ophthalmoplegia. Scoliosis and respiratory insufficiency typically developed early and progressed rapidly, whereas limb weakness was often slowly progressive, and usually did not prevent independent walking. Cardiac involvement was present in 46\% of patients. Relatives of 2 patients had dilated cardiomyopathy. Creatine kinase levels were normal to moderately elevated. Increased fiber size variation, internalized nuclei and cores were common histopathological abnormalities. Cap-like regions, whorled or ring fibers, and mitochondrial accumulations were also observed. Muscle magnetic resonance imaging showed gluteal, hamstring and calf muscle involvement. Western blot analysis showed a near-normal sized titin protein in all samples. The presence of 2 mutations predicted to impact both N2BA and N2B cardiac isoforms appeared to be associated with greatest risk of cardiac involvement. One-third of patients had 1 mutation predicted to impact exons present in fetal skeletal muscle, but not included within the mature skeletal muscle isoform transcript. This strongly suggests developmental isoforms are involved in the pathogenesis of this congenital/early onset disorder.

INTERPRETATION: This detailed clinical reference dataset will greatly facilitate diagnostic confirmation and management of patients, and has provided important insights into disease pathogenesis. Ann Neurol 2018;83:1105-1124.

}, issn = {1531-8249}, doi = {10.1002/ana.25241}, author = {Oates, Emily C and Jones, Kristi J and Donkervoort, Sandra and Charlton, Amanda and Brammah, Susan and Smith, John E and Ware, James S and Yau, Kyle S and Swanson, Lindsay C and Whiffin, Nicola and Peduto, Anthony J and Bournazos, Adam and Waddell, Leigh B and Farrar, Michelle A and Sampaio, Hugo A and Teoh, Hooi Ling and Lamont, Phillipa J and Mowat, David and Fitzsimons, Robin B and Corbett, Alastair J and Ryan, Monique M and O{\textquoteright}Grady, Gina L and Sandaradura, Sarah A and Ghaoui, Roula and Joshi, Himanshu and Marshall, Jamie L and Nolan, Melinda A and Kaur, Simranpreet and Punetha, Jaya and Topf, Ana and Harris, Elizabeth and Bakshi, Madhura and Genetti, Casie A and Marttila, Minttu and Werlauff, Ulla and Streichenberger, Nathalie and Pestronk, Alan and Mazanti, Ingrid and Pinner, Jason R and Vuillerot, Carole and Grosmann, Carla and Camacho, Ana and Mohassel, Payam and Leach, Meganne E and Foley, A Reghan and Bharucha-Goebel, Diana and Collins, James and Connolly, Anne M and Gilbreath, Heather R and Iannaccone, Susan T and Castro, Diana and Cummings, Beryl B and Webster, Richard I and Lazaro, Le{\"\i}la and Vissing, John and Coppens, Sandra and Deconinck, Nicolas and Luk, Ho-Ming and Thomas, Neil H and Foulds, Nicola C and Illingworth, Marjorie A and Ellard, Sian and McLean, Catriona A and Phadke, Rahul and Ravenscroft, Gianina and Witting, Nanna and Hackman, Peter and Richard, Isabelle and Cooper, Sandra T and Kamsteeg, Erik-Jan and Hoffman, Eric P and Bushby, Kate and Straub, Volker and Udd, Bjarne and Ferreiro, Ana and North, Kathryn N and Clarke, Nigel F and Lek, Monkol and Beggs, Alan H and B{\"o}nnemann, Carsten G and MacArthur, Daniel G and Granzier, Henk and Davis, Mark R and Laing, Nigel G} } @article {405, title = {Mutations in sphingosine-1-phosphate lyase cause nephrosis with ichthyosis and adrenal insufficiency.}, journal = {J Clin Invest}, volume = {127}, year = {2017}, month = {2017 Mar 01}, pages = {912-928}, abstract = {

Steroid-resistant nephrotic syndrome (SRNS) causes 15\% of chronic kidney disease cases. A mutation in 1 of over 40 monogenic genes can be detected in approximately 30\% of individuals with SRNS whose symptoms manifest before 25 years of age. However, in many patients, the genetic etiology remains unknown. Here, we have performed whole exome sequencing to identify recessive causes of SRNS. In 7 families with SRNS and facultative ichthyosis, adrenal insufficiency, immunodeficiency, and neurological defects, we identified 9 different recessive mutations in SGPL1, which encodes sphingosine-1-phosphate (S1P) lyase. All mutations resulted in reduced or absent SGPL1 protein and/or enzyme activity. Overexpression of cDNA representing SGPL1 mutations resulted in subcellular mislocalization of SGPL1. Furthermore, expression of WT human SGPL1 rescued growth of SGPL1-deficient dpl1Δ yeast strains, whereas expression of disease-associated variants did not. Immunofluorescence revealed SGPL1 expression in mouse podocytes and mesangial cells. Knockdown of Sgpl1 in rat mesangial cells inhibited cell migration, which was partially rescued by VPC23109, an S1P receptor antagonist. In Drosophila, Sply mutants, which lack SGPL1, displayed a phenotype reminiscent of nephrotic syndrome in nephrocytes. WT Sply, but not the disease-associated variants, rescued this phenotype. Together, these results indicate that SGPL1 mutations cause a syndromic form of SRNS.

}, keywords = {Aldehyde-Lyases, Animals, Cell Line, Cell Movement, Drosophila melanogaster, Drosophila Proteins, Female, Humans, Ichthyosis, Lamellar, Male, Mesangial Cells, Mice, Mice, Knockout, Mutation, Nephrotic Syndrome, Protein Transport, Rats}, issn = {1558-8238}, doi = {10.1172/JCI89626}, author = {Lovric, Svjetlana and Goncalves, Sara and Gee, Heon Yung and Oskouian, Babak and Srinivas, Honnappa and Choi, Won-Il and Shril, Shirlee and Ashraf, Shazia and Tan, Weizhen and Rao, Jia and Airik, Merlin and Schapiro, David and Braun, Daniela A and Sadowski, Carolin E and Widmeier, Eugen and Jobst-Schwan, Tilman and Schmidt, Johanna Magdalena and Girik, Vladimir and Capitani, Guido and Suh, Jung H and Lachauss{\'e}e, No{\"e}lle and Arrondel, Christelle and Patat, Julie and Gribouval, Olivier and Furlano, Monica and Boyer, Olivia and Schmitt, Alain and Vuiblet, Vincent and Hashmi, Seema and Wilcken, Rainer and Bernier, Francois P and Innes, A Micheil and Parboosingh, Jillian S and Lamont, Ryan E and Midgley, Julian P and Wright, Nicola and Majewski, Jacek and Zenker, Martin and Schaefer, Franz and Kuss, Navina and Greil, Johann and Giese, Thomas and Schwarz, Klaus and Catheline, Vilain and Schanze, Denny and Franke, Ingolf and Sznajer, Yves and Truant, Anne S and Adams, Brigitte and D{\'e}sir, Julie and Biemann, Ronald and Pei, York and Ars, Elisabet and Lloberas, Nuria and Madrid, Alvaro and Dharnidharka, Vikas R and Connolly, Anne M and Willing, Marcia C and Cooper, Megan A and Lifton, Richard P and Simons, Matias and Riezman, Howard and Antignac, Corinne and Saba, Julie D and Hildebrandt, Friedhelm} }