Browsing by Author "Pratt, Victoria M."

Now showing 1 - 10 of 57
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    Allelic decomposition and exact genotyping of highly polymorphic and structurally variant genes
    (Springer Nature, 2018-02-26) Numanagić, Ibrahim; Malikić, Salem; Ford, Michael; Qin, Xiang; Toji, Lorraine; Radovich, Milan; Skaar, Todd C.; Pratt, Victoria M.; Berger, Bonnie; Scherer, Steve; Sahinalp, S. Cenk; Medicine, School of Medicine
    High-throughput sequencing provides the means to determine the allelic decomposition for any gene of interest-the number of copies and the exact sequence content of each copy of a gene. Although many clinically and functionally important genes are highly polymorphic and have undergone structural alterations, no high-throughput sequencing data analysis tool has yet been designed to effectively solve the full allelic decomposition problem. Here we introduce a combinatorial optimization framework that successfully resolves this challenging problem, including for genes with structural alterations. We provide an associated computational tool Aldy that performs allelic decomposition of highly polymorphic, multi-copy genes through using whole or targeted genome sequencing data. For a large diverse sequencing data set, Aldy identifies multiple rare and novel alleles for several important pharmacogenes, significantly improving upon the accuracy and utility of current genotyping assays. As more data sets become available, we expect Aldy to become an essential component of genotyping toolkits.
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    Analytical Validation of a Computational Method for Pharmacogenetic Genotyping from Clinical Whole Exome Sequencing
    (Elsevier, 2022) Ly, Reynold C.; Shugg, Tyler; Ratcliff, Ryan; Osei, Wilberforce; Lynnes, Ty C.; Pratt, Victoria M.; Schneider, Bryan P.; Radovich, Milan; Bray, Steven M.; Salisbury, Benjamin A.; Parikh, Baiju; Sahinalp, S. Cenk; Numanagić, Ibrahim; Skaar, Todd C.; Medicine, School of Medicine
    Germline whole exome sequencing from molecular tumor boards has the potential to be repurposed to support clinical pharmacogenomics. However, accurately calling pharmacogenomics-relevant genotypes from exome sequencing data remains challenging. Accordingly, this study assessed the analytical validity of the computational tool, Aldy, in calling pharmacogenomics-relevant genotypes from exome sequencing data for 13 major pharmacogenes. Germline DNA from whole blood was obtained for 164 subjects seen at an institutional molecular solid tumor board. All subjects had whole exome sequencing from Ashion Analytics and panel-based genotyping from an institutional pharmacogenomics laboratory. Aldy version 3.3 was operationalized on the LifeOmic Precision Health Cloud with copy number fixed to two copies per gene. Aldy results were compared with those from genotyping for 56 star allele-defining variants within CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4, CYP3A5, CYP4F2, DPYD, G6PD, NUDT15, SLCO1B1, and TPMT. Read depth was >100× for all variants except CYP3A4∗22. For 75 subjects in the validation cohort, all 3393 Aldy variant calls were concordant with genotyping. Aldy calls for 736 diplotypes containing alleles assessed by both platforms were also concordant. Aldy identified additional star alleles not covered by targeted genotyping for 139 diplotypes. Aldy accurately called variants and diplotypes for 13 major pharmacogenes, except for CYP2D6 variants involving copy number variations, thus allowing repurposing of whole exome sequencing to support clinical pharmacogenomics.
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    Analytical Validation of Variants to Aid in Genotype-Guided Therapy for Oncology
    (Elsevier, 2019) Swart, Marelize; Stansberry, Wesley M.; Pratt, Victoria M.; Medeiros, Elizabeth B.; Kiel, Patrick J.; Shen, Fei; Schneider, Bryan P.; Skaar, Todd C.; Medical and Molecular Genetics, School of Medicine
    The Clinical Laboratory Improvement Amendments (CLIA) of 1988 requires that pharmacogenetic genotyping methods need to be established according to technical standards and laboratory practice guidelines before testing can be offered to patients. Testing methods for variants in ABCB1, CBR3, COMT, CYP3A7, C8ORF34, FCGR2A, FCGR3A, HAS3, NT5C2, NUDT15, SBF2, SEMA3C, SLC16A5, SLC28A3, SOD2, TLR4, and TPMT were validated in a CLIA-accredited laboratory. As no known reference materials were available, DNA samples that were from Coriell Cell Repositories (Camden, NJ) were used for the analytical validation studies. Pharmacogenetic testing methods developed here were shown to be accurate and 100% analytically sensitive and specific. Other CLIA-accredited laboratories interested in offering pharmacogenetic testing for these genetic variants, related to genotype-guided therapy for oncology, could use these publicly available samples as reference materials when developing and validating new genetic tests or refining current assays.
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    BICRA, a SWI/SNF Complex Member, Is Associated with BAF-Disorder Related Phenotypes in Humans and Model Organisms
    (Elsevier, 2020-12-03) Barish, Scott; Barakat, Tahsin Stefan; Michel, Brittany C.; Mashtalir, Nazar; Phillips, Jennifer B.; Valencia, Alfredo M.; Ugur, Berrak; Wegner, Jeremy; Scott, Tiana M.; Bostwick, Brett; Murdock, David R.; Dai, Hongzheng; Perenthaler, Elena; Nikoncuk, Anita; van Slegtenhorst, Marjon; Brooks, Alice S.; Keren, Boris; Nava, Caroline; Mignot, Cyril; Douglas, Jessica; Rodan, Lance; Nowak, Catherine; Ellard, Sian; Stals, Karen; Lynch, Sally Ann; Faoucher, Marie; Lesca, Gaetan; Edery, Patrick; Engleman, Kendra L.; Zhou, Dihong; Thiffault, Isabelle; Herriges, John; Gass, Jennifer; Louie, Raymond J.; Stolerman, Elliot; Washington, Camerun; Vetrini, Francesco; Otsubo, Aiko; Pratt, Victoria M.; Conboy, Erin; Treat, Kayla; Shannon, Nora; Camacho, Jose; Wakeling, Emma; Yuan, Bo; Chen, Chun-An; Rosenfeld, Jill A.; Westerfield, Monte; Wangler, Michael; Yamamoto, Shinya; Kadoch, Cigall; Scott, Daryl A.; Bellen, Hugo J.; Medical and Molecular Genetics, School of Medicine
    SWI/SNF-related intellectual disability disorders (SSRIDDs) are rare neurodevelopmental disorders characterized by developmental disability, coarse facial features, and fifth digit/nail hypoplasia that are caused by pathogenic variants in genes that encode for members of the SWI/SNF (or BAF) family of chromatin remodeling complexes. We have identified 12 individuals with rare variants (10 loss-of-function, 2 missense) in the BICRA (BRD4 interacting chromatin remodeling complex-associated protein) gene, also known as GLTSCR1, which encodes a subunit of the non-canonical BAF (ncBAF) complex. These individuals exhibited neurodevelopmental phenotypes that include developmental delay, intellectual disability, autism spectrum disorder, and behavioral abnormalities as well as dysmorphic features. Notably, the majority of individuals lack the fifth digit/nail hypoplasia phenotype, a hallmark of most SSRIDDs. To confirm the role of BICRA in the development of these phenotypes, we performed functional characterization of the zebrafish and Drosophila orthologs of BICRA. In zebrafish, a mutation of bicra that mimics one of the loss-of-function variants leads to craniofacial defects possibly akin to the dysmorphic facial features seen in individuals harboring putatively pathogenic BICRA variants. We further show that Bicra physically binds to other non-canonical ncBAF complex members, including the BRD9/7 ortholog, CG7154, and is the defining member of the ncBAF complex in flies. Like other SWI/SNF complex members, loss of Bicra function in flies acts as a dominant enhancer of position effect variegation but in a more context-specific manner. We conclude that haploinsufficiency of BICRA leads to a unique SSRIDD in humans whose phenotypes overlap with those previously reported.
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    Building Evidence for Clinical Use of Pharmacogenomics and Reimbursement for Testing
    (Elsevier, 2022) Cavallari, Larisa H.; Pratt, Victoria M.; Medical and Molecular Genetics, School of Medicine
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    Characterization of 137 Genomic DNA Reference Materials for 28 Pharmacogenetic Genes: A GeT-RM Collaborative Project
    (Elsevier, 2016-01) Pratt, Victoria M.; Everts, Robin E.; Aggarwal, Praful; Beyer, Brittany N.; Broeckel, Ulrich; Epstein-Baak, Ruth; Hujsak, Paul; Kornreich, Ruth; Liao, Jun; Lorier, Rachel; Scott, Stuart A.; Smith, Chingying Huang; Toji, Lorraine H.; Turner, Amy; Kalman, Lisa V.; Department of Medical and Molecular Genetics, IU School of Medicine
    Pharmacogenetic testing is increasingly available from clinical laboratories. However, only a limited number of quality control and other reference materials are currently available to support clinical testing. To address this need, the Centers for Disease Control and Prevention-based Genetic Testing Reference Material Coordination Program, in collaboration with members of the pharmacogenetic testing community and the Coriell Cell Repositories, has characterized 137 genomic DNA samples for 28 genes commonly genotyped by pharmacogenetic testing assays (CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4, CYP3A5, CYP4F2, DPYD, GSTM1, GSTP1, GSTT1, NAT1, NAT2, SLC15A2, SLC22A2, SLCO1B1, SLCO2B1, TPMT, UGT1A1, UGT2B7, UGT2B15, UGT2B17, and VKORC1). One hundred thirty-seven Coriell cell lines were selected based on ethnic diversity and partial genotype characterization from earlier testing. DNA samples were coded and distributed to volunteer testing laboratories for targeted genotyping using a number of commercially available and laboratory developed tests. Through consensus verification, we confirmed the presence of at least 108 variant pharmacogenetic alleles. These samples are also being characterized by other pharmacogenetic assays, including next-generation sequencing, which will be reported separately. Genotyping results were consistent among laboratories, with most differences in allele assignments attributed to assay design and variability in reported allele nomenclature, particularly for CYP2D6, UGT1A1, and VKORC1. These publicly available samples will help ensure the accuracy of pharmacogenetic testing.
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    Characterization of Reference Materials for Genetic Testing of CYP2D6 Alleles: A GeT-RM Collaborative Project
    (Elsevier, 2019-11) Gaedigk, Andrea; Turner, Amy; Everts, Robin E.; Scott, Stuart A.; Aggarwal, Praful; Broeckel, Ulrich; McMillin, Gwendolyn A.; Melis, Roberta; Boone, Erin C.; Pratt, Victoria M.; Kalman, Lisa V.; Medical and Molecular Genetics, School of Medicine
    Pharmacogenetic testing increasingly is available from clinical and research laboratories. However, only a limited number of quality control and other reference materials currently are available for the complex rearrangements and rare variants that occur in the CYP2D6 gene. To address this need, the Division of Laboratory Systems, CDC-based Genetic Testing Reference Material Coordination Program, in collaboration with members of the pharmacogenetic testing and research communities and the Coriell Cell Repositories (Camden, NJ), has characterized 179 DNA samples derived from Coriell cell lines. Testing included the recharacterization of 137 genomic DNAs that were genotyped in previous Genetic Testing Reference Material Coordination Program studies and 42 additional samples that had not been characterized previously. DNA samples were distributed to volunteer testing laboratories for genotyping using a variety of commercially available and laboratory-developed tests. These publicly available samples will support the quality-assurance and quality-control programs of clinical laboratories performing CYP2D6 testing.
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    Characterization of Reference Materials for Spinal Muscular Atrophy Genetic Testing: A Genetic Testing Reference Materials Coordination Program Collaborative Project
    (Elsevier, 2021) Prior, Thomas W.; Bayrak-Toydemir, Pinar; Lynnes, Ty C.; Mao, Rong; Metcalf, James D.; Muralidharan, Kasinathan; Iwata-Otsubo, Aiko; Pham, Ha T.; Pratt, Victoria M.; Qureshi, Shumaila; Requesens, Deborah; Shen, Junqing; Vetrini, Francesco; Kalman, Lisa; Medicine, School of Medicine
    Spinal muscular atrophy (SMA) is an autosomal recessive disorder predominately caused by bi-allelic loss of the SMN1 gene. Increased copies of SMN2, a low functioning nearly identical paralog, are associated with a less severe phenotype. SMA was recently recommended for inclusion in newborn screening. Clinical laboratories must accurately measure SMN1 and SMN2 copy number to identify SMA patients and carriers, and to identify individuals likely to benefit from therapeutic interventions. Having publicly available and appropriately characterized reference materials with various combinations of SMN1 and SMN2 copy number variants is critical to assure accurate SMA clinical testing. To address this need, the CDC-based Genetic Testing Reference Materials Coordination Program, in collaboration with members of the genetic testing community and the Coriell Institute for Medical Research, has characterized 15 SMA reference materials derived from publicly available cell lines. DNA samples were distributed to four volunteer testing laboratories for genotyping using three different methods. The characterized samples had zero to four copies of SMN1 and zero to five copies SMN2. The samples also contained clinically important allele combinations (eg, zero copies SMN1, three copies SMN2), and several had markers indicative of an SMA carrier. These and other reference materials characterized by the Genetic Testing Reference Materials Coordination Program are available from the Coriell Institute and are proposed to support the quality of clinical laboratory testing.
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    Characterization of Reference Materials for TPMT and NUDT15: A GeT-RM Collaborative Project
    (Elsevier, 2022-10) Pratt, Victoria M.; Wang, Wendy Y.; Boone, Erin C.; Broeckel, Ulrich; Cody, Neal; Edelmann, Lisa; Gaedigk , Andrea; Lynnes, Ty C.; Medeiros, Elizabeth B.; Moyer, Ann M.; Mitchell, Matthew W.; Scott, Stuart A.; Starostik, Petr; Turner, Amy; Kalman, Lisa V.; Medical and Molecular Genetics, School of Medicine
    Pharmacogenetic testing is increasingly provided by clinical and research laboratories; however, only a limited number of quality control and reference materials are currently available for many of the TPMT and NUDT15 variants included in clinical tests. To address this need, the Division of Laboratory Systems, Centers for Disease Control and Prevention–based Genetic Testing Reference Material (GeT-RM) coordination program, in collaboration with members of the pharmacogenetic testing and research communities and the Coriell Institute for Medical Research, has characterized 19 DNA samples derived from Coriell cell lines. DNA samples were distributed to four volunteer testing laboratories for genotyping using a variety of commercially available and laboratory developed tests and/or Sanger sequencing. Of the 12 samples characterized for TPMT, newly identified variants include TPMT∗2, ∗6, ∗12, ∗16, ∗21, ∗24, ∗32, ∗33, and ∗40; for the 7 NUDT15 reference material samples, newly identified variants are NUDT15∗2, ∗3, ∗4, ∗5, ∗6, and ∗9. In addition, a novel haplotype, TPMT∗46, was identified in this study. Preexisting data on an additional 11 Coriell samples, as well as some supplemental testing, were used to create comprehensive reference material panels for TPMT and NUDT15. These publicly available and well-characterized materials can be used to support the quality assurance and quality control programs of clinical laboratories performing clinical pharmacogenetic testing.
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    Characterization of Reference Materials with an Association for Molecular Pathology Pharmacogenetics Working Group Tier 2 Status: CYP2C9, CYP2C19, VKORC1, CYP2C Cluster Variant, and GGCX: A GeT-RM Collaborative Project
    (Elsevier, 2021) Pratt, Victoria M.; Turner, Amy; Broeckel, Ulrich; Dawson, D. Brian; Gaedigk, Andrea; Lynnes, Ty C.; Medeiros, Elizabeth B.; Moyer, Ann M.; Requesens, Deborah; Vetrini, Francesco; Kalman, Lisa V.; Medical and Molecular Genetics, School of Medicine
    Pharmacogenetic testing is increasingly available from clinical and research laboratories. However, only a limited number of quality control and other reference materials are currently available for many of the variants that are tested. The Association for Molecular Pathology Pharmacogenetic Work Group has published a series of papers recommending alleles for inclusion in clinical testing. Several of the alleles were not considered for tier 1 because of a lack of reference materials. To address this need, the Division of Laboratory Systems, Centers for Disease Control and Prevention-based Genetic Testing Reference Material (GeT-RM) program, in collaboration with members of the pharmacogenetic testing and research communities and the Coriell Institute for Medical Research, has characterized 18 DNA samples derived from Coriell cell lines. DNA samples were distributed to five volunteer testing laboratories for genotyping using three commercially available and laboratory developed tests. Several tier 2 variants, including CYP2C9∗13, CYP2C19∗35, the CYP2C cluster variant (rs12777823), two variants in VKORC1 (rs61742245 and rs72547529) related to warfarin resistance, and two variants in GGCX (rs12714145 and rs11676382) related to clotting factor activation, were identified among these samples. These publicly available materials complement the pharmacogenetic reference materials previously characterized by the GeT-RM program and will support the quality assurance and quality control programs of clinical laboratories that perform pharmacogenetic testing.