@article {619, title = {Genetic and mechanistic diversity in pediatric hemophagocytic lymphohistiocytosis.}, journal = {Blood}, volume = {132}, year = {2018}, month = {2018 Jul 05}, pages = {89-100}, abstract = {

The HLH-2004 criteria are used to diagnose hemophagocytic lymphohistiocytosis (HLH), yet concern exists for their misapplication, resulting in suboptimal treatment of some patients. We sought to define the genomic spectrum and associated outcomes of a diverse cohort of children who met the HLH-2004 criteria. Genetic testing was performed clinically or through research-based whole-exome sequencing. Clinical metrics were analyzed with respect to genomic results. Of 122 subjects enrolled over the course of 17 years, 101 subjects received genetic testing. Biallelic familial HLH (fHLH) gene defects were identified in only 19 (19\%) and correlated with presentation at younger than 1 year of age ( < .0001). Digenic fHLH variants were observed but lacked statistical support for disease association. In 28 (58\%) of 48 subjects, research whole-exome sequencing analyses successfully identified likely molecular explanations, including underlying primary immunodeficiency diseases, dysregulated immune activation and proliferation disorders, and potentially novel genetic conditions. Two-thirds of patients identified by the HLH-2004 criteria had underlying etiologies for HLH, including genetic defects, autoimmunity, and malignancy. Overall survival was 45\%, and increased mortality correlated with HLH triggered by infection or malignancy ( < .05). Differences in survival did not correlate with genetic profile or extent of therapy. HLH should be conceptualized as a phenotype of critical illness characterized by toxic activation of immune cells from different underlying mechanisms. In most patients with HLH, targeted sequencing of fHLH genes remains insufficient for identifying pathogenic mechanisms. Whole-exome sequencing, however, may identify specific therapeutic opportunities and affect hematopoietic stem cell transplantation options for these patients.

}, issn = {1528-0020}, doi = {10.1182/blood-2017-11-814244}, author = {Chinn, Ivan K and Eckstein, Olive S and Peckham-Gregory, Erin C and Goldberg, Baruch R and Forbes, Lisa R and Nicholas, Sarah K and Mace, Emily M and Vogel, Tiphanie P and Abhyankar, Harshal A and Diaz, Maria I and Heslop, Helen E and Krance, Robert A and Martinez, Caridad A and Nguyen, Trung C and Bashir, Dalia A and Goldman, Jordana R and Stray-Pedersen, Asbj{\o}rg and Pedroza, Luis A and Poli, M Cecilia and Aldave-Becerra, Juan C and McGhee, Sean A and Al-Herz, Waleed and Chamdin, Aghiad and Coban-Akdemir, Zeynep H and Jhangiani, Shalini N and Muzny, Donna M and Cao, Tram N and Hong, Diana N and Gibbs, Richard A and Lupski, James R and Orange, Jordan S and McClain, Kenneth L and Allen, Carl E} } @article {27, title = {Primary immunodeficiency diseases: Genomic approaches delineate heterogeneous Mendelian disorders.}, journal = {J Allergy Clin Immunol}, volume = {139}, year = {2017}, month = {2017 Jan}, pages = {232-245}, abstract = {

BACKGROUND: Primary immunodeficiency diseases (PIDDs) are clinically and genetically heterogeneous disorders thus far associated with mutations in more than 300 genes. The clinical phenotypes derived from distinct genotypes can overlap. Genetic etiology can be a prognostic indicator of disease severity and can influence treatment decisions.

OBJECTIVE: We sought to investigate the ability of whole-exome screening methods to detect disease-causing variants in patients with PIDDs.

METHODS: Patients with PIDDs from 278 families from 22 countries were investigated by using whole-exome sequencing. Computational copy number variant (CNV) prediction pipelines and an exome-tiling chromosomal microarray were also applied to identify intragenic CNVs. Analytic approaches initially focused on 475 known or candidate PIDD genes but were nonexclusive and further tailored based on clinical data, family history, and immunophenotyping.

RESULTS: A likely molecular diagnosis was achieved in 110 (40\%) unrelated probands. Clinical diagnosis was revised in about half (60/110) and management was directly altered in nearly a quarter (26/110) of families based on molecular findings. Twelve PIDD-causing CNVs were detected, including 7 smaller than 30~Kb that would not have been detected with conventional diagnostic CNV arrays.

CONCLUSION: This high-throughput genomic approach enabled detection of disease-related variants in unexpected genes; permitted detection of low-grade constitutional, somatic, and revertant mosaicism; and provided evidence of a mutational burden in mixed PIDD immunophenotypes.

}, keywords = {Adolescent, Adult, Aged, Child, Child, Preschool, DNA Copy Number Variations, Female, Genomics, High-Throughput Nucleotide Sequencing, Humans, Immunologic Deficiency Syndromes, Infant, Male, Middle Aged, Young Adult}, issn = {1097-6825}, doi = {10.1016/j.jaci.2016.05.042}, author = {Stray-Pedersen, Asbj{\o}rg and Sorte, Hanne S{\o}rmo and Samarakoon, Pubudu and Gambin, Tomasz and Chinn, Ivan K and Coban Akdemir, Zeynep H and Erichsen, Hans Christian and Forbes, Lisa R and Gu, Shen and Yuan, Bo and Jhangiani, Shalini N and Muzny, Donna M and R{\o}dningen, Olaug Kristin and Sheng, Ying and Nicholas, Sarah K and Noroski, Lenora M and Seeborg, Filiz O and Davis, Carla M and Canter, Debra L and Mace, Emily M and Vece, Timothy J and Allen, Carl E and Abhyankar, Harshal A and Boone, Philip M and Beck, Christine R and Wiszniewski, Wojciech and Fevang, B{\o}rre and Aukrust, P{\r a}l and Tj{\o}nnfjord, Geir E and Gedde-Dahl, Tobias and Hjorth-Hansen, Henrik and Dybedal, Ingunn and Nord{\o}y, Ingvild and J{\o}rgensen, Silje F and Abrahamsen, Tore G and {\O}verland, Torstein and Bechensteen, Anne Grete and Skogen, Vegard and Osnes, Liv T N and Kulseth, Mari Ann and Prescott, Trine E and Rustad, Cecilie F and Heimdal, Ketil R and Belmont, John W and Rider, Nicholas L and Chinen, Javier and Cao, Tram N and Smith, Eric A and Caldirola, Maria Soledad and Bezrodnik, Liliana and Lugo Reyes, Saul Oswaldo and Espinosa Rosales, Francisco J and Guerrero-Cursaru, Nina Denisse and Pedroza, Luis Alberto and Poli, Cecilia M and Franco, Jose L and Trujillo Vargas, Claudia M and Aldave Becerra, Juan Carlos and Wright, Nicola and Issekutz, Thomas B and Issekutz, Andrew C and Abbott, Jordan and Caldwell, Jason W and Bayer, Diana K and Chan, Alice Y and Aiuti, Alessandro and Cancrini, Caterina and Holmberg, Eva and West, Christina and Burstedt, Magnus and Karaca, Ender and Yesil, G{\"o}zde and Artac, Hasibe and Bayram, Yavuz and Atik, Mehmed Musa and Eldomery, Mohammad K and Ehlayel, Mohammad S and Jolles, Stephen and Flat{\o}, Berit and Bertuch, Alison A and Hanson, I Celine and Zhang, Victor W and Wong, Lee-Jun and Hu, Jianhong and Walkiewicz, Magdalena and Yang, Yaping and Eng, Christine M and Boerwinkle, Eric and Gibbs, Richard A and Shearer, William T and Lyle, Robert and Orange, Jordan S and Lupski, James R} }