@article {532, title = {Rapid molecular diagnostics of severe primary immunodeficiency determined by using targeted next-generation sequencing.}, journal = {J Allergy Clin Immunol}, volume = {138}, year = {2016}, month = {2016 10}, pages = {1142-1151.e2}, abstract = {

BACKGROUND: Primary immunodeficiency diseases (PIDDs) are inherited disorders of the immune system. The most severe form, severe combined immunodeficiency (SCID), presents with profound deficiencies of T~cells, B~cells, or both at birth. If not treated promptly, affected patients usually do not live beyond infancy because of infections. Genetic heterogeneity of SCID frequently delays the diagnosis; a specific diagnosis is crucial for life-saving treatment and optimal management.

OBJECTIVE: We developed a next-generation sequencing (NGS)-based multigene-targeted panel for SCID and other severe PIDDs requiring rapid therapeutic actions in a clinical laboratory setting.

METHODS: The target gene capture/NGS assay provides an average read depth of approximately 1000{\texttimes}. The deep coverage facilitates simultaneous detection of single nucleotide variants and exonic copy number variants in one comprehensive assessment. Exons with insufficient coverage (<20{\texttimes} read depth) or high sequence homology (pseudogenes) are complemented by amplicon-based sequencing with specific primers to ensure 100\% coverage of all targeted regions.

RESULTS: Analysis of 20 patient samples with low T-cell receptor excision circle numbers on newborn screening or a positive family history or clinical suspicion of SCID or other severe PIDD identified deleterious mutations in 14 of them. Identified pathogenic variants included both single nucleotide variants and exonic copy number variants, such as hemizygous nonsense, frameshift, and missense changes in IL2RG; compound heterozygous changes in ATM, RAG1, and CIITA; homozygous changes in DCLRE1C and IL7R; and a heterozygous nonsense mutation in CHD7.

CONCLUSION: High-throughput deep sequencing analysis with complete clinical validation greatly increases the diagnostic yield of severe primary immunodeficiency. Establishing a molecular diagnosis enables early immune reconstitution through prompt therapeutic intervention and guides management for improved long-term quality of life.

}, keywords = {Adolescent, Child, Female, Genetic Variation, Humans, Male, Pathology, Molecular, Sequence Analysis, DNA, Severe Combined Immunodeficiency}, issn = {1097-6825}, doi = {10.1016/j.jaci.2016.05.035}, author = {Yu, Hui and Zhang, Victor Wei and Stray-Pedersen, Asbj{\o}rg and Hanson, Imelda Celine and Forbes, Lisa R and de la Morena, M Teresa and Chinn, Ivan K and Gorman, Elizabeth and Mendelsohn, Nancy J and Pozos, Tamara and Wiszniewski, Wojciech and Nicholas, Sarah K and Yates, Anne B and Moore, Lindsey E and Berge, Knut Erik and Sorte, Hanne and Bayer, Diana K and ALZahrani, Daifulah and Geha, Raif S and Feng, Yanming and Wang, Guoli and Orange, Jordan S and Lupski, James R and Wang, Jing and Wong, Lee-Jun} } @article {182, title = {Genetic linkage analysis in the age of whole-genome sequencing.}, journal = {Nat Rev Genet}, volume = {16}, year = {2015}, month = {2015 May}, pages = {275-84}, abstract = {

For many years, linkage analysis was the primary tool used for the genetic mapping of Mendelian and complex traits with familial aggregation. Linkage analysis was largely supplanted by the wide adoption of genome-wide association studies (GWASs). However, with the recent increased use of whole-genome sequencing (WGS), linkage analysis is again emerging as an important and powerful analysis method for the identification of genes involved in disease aetiology, often in conjunction with WGS filtering approaches. Here, we review the principles of linkage analysis and provide practical guidelines for carrying out linkage studies using WGS data.

}, keywords = {Algorithms, Female, Genetic Linkage, Genome, Human, Genome-Wide Association Study, Genotyping Techniques, Humans, Lod Score, Male, Pedigree, Penetrance, Phenotype, Polymorphism, Single Nucleotide, Sequence Analysis, DNA, Software}, issn = {1471-0064}, doi = {10.1038/nrg3908}, author = {Ott, Jurg and Wang, Jing and Leal, Suzanne M} }