@article {357, title = {Lessons learned from additional research analyses of unsolved clinical exome cases.}, journal = {Genome Med}, volume = {9}, year = {2017}, month = {2017 03 21}, pages = {26}, abstract = {

BACKGROUND: Given the rarity of most single-gene Mendelian disorders, concerted efforts of data exchange between clinical and scientific communities are critical to optimize molecular diagnosis and novel disease gene discovery.

METHODS: We designed and implemented protocols for the study of cases for which a plausible molecular diagnosis was not achieved in a clinical genomics diagnostic laboratory (i.e. unsolved clinical exomes). Such cases were recruited to a research laboratory for further analyses, in order to potentially: (1) accelerate novel disease gene discovery; (2) increase the molecular diagnostic yield of whole exome sequencing (WES); and (3) gain insight into the genetic mechanisms of disease. Pilot project data included 74 families, consisting mostly of parent-offspring trios. Analyses performed on a research basis employed both WES from additional family members and complementary bioinformatics approaches and protocols.

RESULTS: Analysis of all possible modes of Mendelian inheritance, focusing on both single nucleotide variants (SNV) and copy number variant (CNV) alleles, yielded a likely contributory variant in 36\% (27/74) of cases. If one includes candidate genes with variants identified within a single family, a potential contributory variant was identified in a total of ~51\% (38/74) of cases enrolled in this pilot study. The molecular diagnosis was achieved in 30/63 trios (47.6\%). Besides this, the analysis workflow yielded evidence for pathogenic variants in disease-associated genes in 4/6 singleton cases (66.6\%), 1/1 multiplex family involving three affected siblings, and 3/4 (75\%) quartet families. Both the analytical pipeline and the collaborative efforts between the diagnostic and research laboratories provided insights that allowed recent disease gene discoveries (PURA, TANGO2, EMC1, GNB5, ATAD3A, and MIPEP) and increased the number of novel genes, defined in this study as genes identified in more than one family (DHX30 and EBF3).

CONCLUSION: An efficient genomics pipeline in which clinical sequencing in a diagnostic laboratory is followed by the detailed reanalysis of unsolved cases in a research environment, supplemented with WES data from additional family members, and subject to adjuvant bioinformatics analyses including relaxed variant filtering parameters in informatics pipelines, can enhance the molecular diagnostic yield and provide mechanistic insights into Mendelian disorders. Implementing these approaches requires collaborative clinical molecular diagnostic and research efforts.

}, keywords = {Adenosine Triphosphatases, ATPases Associated with Diverse Cellular Activities, Computational Biology, DNA Copy Number Variations, DNA-Binding Proteins, Exome, Female, Genetic Diseases, Inborn, Genomics, GTP-Binding Protein beta Subunits, Humans, Male, Membrane Proteins, Metalloendopeptidases, Mitochondrial Proteins, Pilot Projects, Polymorphism, Single Nucleotide, Sequence Analysis, DNA, Transcription Factors}, issn = {1756-994X}, doi = {10.1186/s13073-017-0412-6}, author = {Eldomery, Mohammad K and Coban-Akdemir, Zeynep and Harel, Tamar and Rosenfeld, Jill A and Gambin, Tomasz and Stray-Pedersen, Asbj{\o}rg and K{\"u}ry, S{\'e}bastien and Mercier, Sandra and Lessel, Davor and Denecke, Jonas and Wiszniewski, Wojciech and Penney, Samantha and Liu, Pengfei and Bi, Weimin and Lalani, Seema R and Schaaf, Christian P and Wangler, Michael F and Bacino, Carlos A and Lewis, Richard Alan and Potocki, Lorraine and Graham, Brett H and Belmont, John W and Scaglia, Fernando and Orange, Jordan S and Jhangiani, Shalini N and Chiang, Theodore and Doddapaneni, Harsha and Hu, Jianhong and Muzny, Donna M and Xia, Fan and Beaudet, Arthur L and Boerwinkle, Eric and Eng, Christine M and Plon, Sharon E and Sutton, V Reid and Gibbs, Richard A and Posey, Jennifer E and Yang, Yaping and Lupski, James R} } @article {337, title = {Loss of Nardilysin, a Mitochondrial Co-chaperone for α-Ketoglutarate Dehydrogenase, Promotes mTORC1 Activation and Neurodegeneration.}, journal = {Neuron}, volume = {93}, year = {2017}, month = {2017 Jan 04}, pages = {115-131}, abstract = {

We previously identified mutations in Nardilysin (dNrd1) in a forward genetic screen designed to isolate genes whose loss causes neurodegeneration in Drosophila photoreceptor neurons. Here~we show that NRD1 is localized to mitochondria, where it recruits mitochondrial chaperones and assists in the folding of α-ketoglutarate dehydrogenase (OGDH), a rate-limiting enzyme in~the Krebs cycle. Loss of Nrd1 or Ogdh leads to an increase in α-ketoglutarate, a substrate for OGDH,~which in turn leads to mTORC1 activation and a subsequent reduction in autophagy. Inhibition of mTOR activity by rapamycin or partially restoring autophagy delays neurodegeneration in dNrd1 mutant flies. In summary, this study reveals a novel role for NRD1 as a mitochondrial co-chaperone for OGDH and provides a mechanistic link between mitochondrial metabolic dysfunction, mTORC1 signaling, and impaired autophagy in neurodegeneration.

}, keywords = {Animals, Autophagy, Drosophila, Drosophila melanogaster, Drosophila Proteins, Ketoglutarate Dehydrogenase Complex, Ketoglutaric Acids, Lysine, Mechanistic Target of Rapamycin Complex 1, Metalloendopeptidases, Mitochondria, Molecular Chaperones, Multiprotein Complexes, Neurodegenerative Diseases, TOR Serine-Threonine Kinases}, issn = {1097-4199}, doi = {10.1016/j.neuron.2016.11.038}, author = {Yoon, Wan Hee and Sandoval, Hector and Nagarkar-Jaiswal, Sonal and Jaiswal, Manish and Yamamoto, Shinya and Haelterman, Nele A and Putluri, Nagireddy and Putluri, Vasanta and Sreekumar, Arun and Tos, Tulay and Aksoy, Ayse and Donti, Taraka and Graham, Brett H and Ohno, Mikiko and Nishi, Eiichiro and Hunter, Jill and Muzny, Donna M and Carmichael, Jason and Shen, Joseph and Arboleda, Valerie A and Nelson, Stanley F and Wangler, Michael F and Karaca, Ender and Lupski, James R and Bellen, Hugo J} } @article {634, title = {Mutations in KEOPS-complex genes cause nephrotic syndrome with primary microcephaly.}, journal = {Nat Genet}, volume = {49}, year = {2017}, month = {2017 Oct}, pages = {1529-1538}, abstract = {

Galloway-Mowat syndrome (GAMOS) is an autosomal-recessive disease characterized by the combination of early-onset nephrotic syndrome (SRNS) and microcephaly with brain anomalies. Here we identified recessive mutations in OSGEP, TP53RK, TPRKB, and LAGE3, genes encoding the four subunits of the KEOPS complex, in 37 individuals from 32 families with GAMOS. CRISPR-Cas9 knockout in zebrafish and mice recapitulated the human phenotype of primary microcephaly and resulted in early lethality. Knockdown of OSGEP, TP53RK, or TPRKB inhibited cell proliferation, which human mutations did not rescue. Furthermore, knockdown of these genes impaired protein translation, caused endoplasmic reticulum stress, activated DNA-damage-response signaling, and ultimately induced apoptosis. Knockdown of OSGEP or TP53RK induced defects in the actin cytoskeleton and decreased the migration rate of human podocytes, an established intermediate phenotype of SRNS. We thus identified four new monogenic causes of GAMOS, describe a link between KEOPS function and human disease, and delineate potential pathogenic mechanisms.

}, keywords = {Animals, Apoptosis, Carrier Proteins, Cell Movement, CRISPR-Cas Systems, Cytoskeleton, DNA Repair, Endoplasmic Reticulum Stress, Gene Knockout Techniques, Hernia, Hiatal, Humans, Intracellular Signaling Peptides and Proteins, Metalloendopeptidases, Mice, Microcephaly, Models, Molecular, Multiprotein Complexes, Mutation, Nephrosis, Nephrotic Syndrome, Podocytes, Protein Conformation, Protein-Serine-Threonine Kinases, RNA Processing, Post-Transcriptional, RNA, Transfer, Telomere Homeostasis, Zebrafish, Zebrafish Proteins}, issn = {1546-1718}, doi = {10.1038/ng.3933}, author = {Braun, Daniela A and Rao, Jia and Mollet, Geraldine and Schapiro, David and Daugeron, Marie-Claire and Tan, Weizhen and Gribouval, Olivier and Boyer, Olivia and Revy, Patrick and Jobst-Schwan, Tilman and Schmidt, Johanna Magdalena and Lawson, Jennifer A and Schanze, Denny and Ashraf, Shazia and Ullmann, Jeremy F P and Hoogstraten, Charlotte A and Boddaert, Nathalie and Collinet, Bruno and Martin, Ga{\"e}lle and Liger, Dominique and Lovric, Svjetlana and Furlano, Monica and Guerrera, I Chiara and Sanchez-Ferras, Oraly and Hu, Jennifer F and Boschat, Anne-Claire and Sanquer, Sylvia and Menten, Bj{\"o}rn and Vergult, Sarah and De Rocker, Nina and Airik, Merlin and Hermle, Tobias and Shril, Shirlee and Widmeier, Eugen and Gee, Heon Yung and Choi, Won-Il and Sadowski, Carolin E and Pabst, Werner L and Warejko, Jillian K and Daga, Ankana and Basta, Tamara and Matejas, Verena and Scharmann, Karin and Kienast, Sandra D and Behnam, Babak and Beeson, Brendan and Begtrup, Amber and Bruce, Malcolm and Ch{\textquoteright}ng, Gaik-Siew and Lin, Shuan-Pei and Chang, Jui-Hsing and Chen, Chao-Huei and Cho, Megan T and Gaffney, Patrick M and Gipson, Patrick E and Hsu, Chyong-Hsin and Kari, Jameela A and Ke, Yu-Yuan and Kiraly-Borri, Cathy and Lai, Wai-Ming and Lemyre, Emmanuelle and Littlejohn, Rebecca Okashah and Masri, Amira and Moghtaderi, Mastaneh and Nakamura, Kazuyuki and Ozaltin, Fatih and Praet, Marleen and Prasad, Chitra and Prytula, Agnieszka and Roeder, Elizabeth R and Rump, Patrick and Schnur, Rhonda E and Shiihara, Takashi and Sinha, Manish D and Soliman, Neveen A and Soulami, Kenza and Sweetser, David A and Tsai, Wen-Hui and Tsai, Jeng-Daw and Topaloglu, Rezan and Vester, Udo and Viskochil, David H and Vatanavicharn, Nithiwat and Waxler, Jessica L and Wierenga, Klaas J and Wolf, Matthias T F and Wong, Sik-Nin and Leidel, Sebastian A and Truglio, Gessica and Dedon, Peter C and Poduri, Annapurna and Mane, Shrikant and Lifton, Richard P and Bouchard, Maxime and Kannu, Peter and Chitayat, David and Magen, Daniella and Callewaert, Bert and van Tilbeurgh, Herman and Zenker, Martin and Antignac, Corinne and Hildebrandt, Friedhelm} } @article {10, title = {MIPEP recessive variants cause a syndrome of left ventricular non-compaction, hypotonia, and infantile death.}, journal = {Genome Med}, volume = {8}, year = {2016}, month = {2016 Nov 01}, pages = {106}, abstract = {

BACKGROUND: Mitochondrial presequence proteases perform fundamental functions as they process about 70~\% of all mitochondrial preproteins that are encoded in the nucleus and imported posttranslationally. The mitochondrial intermediate presequence protease MIP/Oct1, which carries out precursor processing, has not yet been established to have a role in human disease.

METHODS: Whole exome sequencing was performed on four unrelated probands with left ventricular non-compaction (LVNC), developmental delay (DD), seizures, and severe hypotonia. Proposed pathogenic variants were confirmed by Sanger sequencing or array comparative genomic hybridization. Functional analysis of the identified MIP variants was performed using the model organism Saccharomyces cerevisiae as the protein and its functions are highly conserved from yeast to human.

RESULTS: Biallelic single nucleotide variants (SNVs) or copy number variants (CNVs) in MIPEP, which encodes MIP, were present in all four probands, three of whom had infantile/childhood death. Two patients had compound heterozygous SNVs (p.L582R/p.L71Q and p.E602*/p.L306F) and one patient from a consanguineous family had a homozygous SNV (p.K343E). The fourth patient, identified through the GeneMatcher tool, a part of the Matchmaker Exchange Project, was found to have inherited a paternal SNV (p.H512D) and a maternal CNV (1.4-Mb deletion of 13q12.12) that includes MIPEP. All amino acids affected in the patients{\textquoteright} missense variants are highly conserved from yeast to human and therefore S. cerevisiae was employed for functional analysis (for p.L71Q, p.L306F, and p.K343E). The mutations p.L339F (human p.L306F) and p.K376E (human p.K343E) resulted in a severe decrease of Oct1 protease activity and accumulation of non-processed Oct1 substrates and consequently impaired viability under respiratory growth conditions. The p.L83Q (human p.L71Q) failed to localize to the mitochondria.

CONCLUSIONS: Our findings reveal for the first time the role of the mitochondrial intermediate peptidase in human disease. Loss of MIP function results in a syndrome which consists of LVNC, DD, seizures, hypotonia, and cataracts. Our approach highlights the power of data exchange and the importance of an interrelationship between clinical and research efforts for disease gene discovery.

}, keywords = {Adult, Amino Acid Sequence, Female, Genes, Recessive, Heart Defects, Congenital, Humans, Infant, Infant, Newborn, Male, Metalloendopeptidases, Muscle Hypotonia, Pedigree, Phenotype, Sequence Homology, Amino Acid, Sudden Infant Death, Syndrome}, issn = {1756-994X}, doi = {10.1186/s13073-016-0360-6}, author = {Eldomery, Mohammad K and Akdemir, Zeynep C and V{\"o}gtle, F-Nora and Charng, Wu-Lin and Mulica, Patrycja and Rosenfeld, Jill A and Gambin, Tomasz and Gu, Shen and Burrage, Lindsay C and Al Shamsi, Aisha and Penney, Samantha and Jhangiani, Shalini N and Zimmerman, Holly H and Muzny, Donna M and Wang, Xia and Tang, Jia and Medikonda, Ravi and Ramachandran, Prasanna V and Wong, Lee-Jun and Boerwinkle, Eric and Gibbs, Richard A and Eng, Christine M and Lalani, Seema R and Hertecant, Jozef and Rodenburg, Richard J and Abdul-Rahman, Omar A and Yang, Yaping and Xia, Fan and Wang, Meng C and Lupski, James R and Meisinger, Chris and Sutton, V Reid} } @article {314, title = {Mutations in ECEL1 cause distal arthrogryposis type 5D.}, journal = {Am J Hum Genet}, volume = {92}, year = {2013}, month = {2013 Jan 10}, pages = {150-6}, abstract = {

Distal arthrogryposis (DA) syndromes are the most common of the heritable congenital-contracture disorders, and ~50\% of cases are caused by mutations in genes that encode contractile proteins of skeletal myofibers. DA type 5D (DA5D) is a rare, autosomal-recessive DA previously defined by us and is characterized by congenital contractures of the hands and feet, along with distinctive facial features, including ptosis. We used linkage analysis and whole-genome sequencing of a multiplex consanguineous family to identify in endothelin-converting enzyme-like 1 (ECEL1) mutations that result in DA5D. Evaluation of a total of seven families affected by DA5D revealed in five families ECEL1 mutations that explain ~70\% of cases overall. ECEL1 encodes a neuronal endopeptidase and is expressed in the brain and peripheral nerves. Mice deficient in Ecel1 exhibit perturbed terminal branching of motor neurons to the endplate of skeletal muscles, resulting in poor formation of the neuromuscular junction. Our results distinguish a second developmental pathway that causes congenital-contracture syndromes.

}, keywords = {Arthrogryposis, Consanguinity, Female, Genetic Linkage, Humans, Male, Metalloendopeptidases, Mutation, Sequence Analysis, DNA}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2012.11.014}, author = {McMillin, Margaret J and Below, Jennifer E and Shively, Kathryn M and Beck, Anita E and Gildersleeve, Heidi I and Pinner, Jason and Gogola, Gloria R and Hecht, Jacqueline T and Grange, Dorothy K and Harris, David J and Earl, Dawn L and Jagadeesh, Sujatha and Mehta, Sarju G and Robertson, Stephen P and Swanson, James M and Faustman, Elaine M and Mefford, Heather C and Shendure, Jay and Nickerson, Deborah A and Bamshad, Michael J} }