Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
60
result(s) for
"Kulkarni Shashikant"
Sort by:
Best practices for the interpretation and reporting of clinical whole genome sequencing
2022
Whole genome sequencing (WGS) shows promise as a first-tier diagnostic test for patients with rare genetic disorders. However, standards addressing the definition and deployment practice of a best-in-class test are lacking. To address these gaps, the Medical Genome Initiative, a consortium of leading health care and research organizations in the US and Canada, was formed to expand access to high quality clinical WGS by convening experts and publishing best practices. Here, we present best practice recommendations for the interpretation and reporting of clinical diagnostic WGS, including discussion of challenges and emerging approaches that will be critical to harness the full potential of this comprehensive test.
Journal Article
Non-invasive prenatal sequencing for multiple Mendelian monogenic disorders using circulating cell-free fetal DNA
by
Chen, Stella
,
Yang, Yaping
,
Purgason, Anne
in
631/208/514/2254
,
692/53/2421
,
692/700/139/1512
2019
Current non-invasive prenatal screening is targeted toward the detection of chromosomal abnormalities in the fetus
1
,
2
. However, screening for many dominant monogenic disorders associated with de novo mutations is not available, despite their relatively high incidence
3
. Here we report on the development and validation of, and early clinical experience with, a new approach for non-invasive prenatal sequencing for a panel of causative genes for frequent dominant monogenic diseases. Cell-free DNA (cfDNA) extracted from maternal plasma was barcoded, enriched, and then analyzed by next-generation sequencing (NGS) for targeted regions. Low-level fetal variants were identified by a statistical analysis adjusted for NGS read count and fetal fraction. Pathogenic or likely pathogenic variants were confirmed by a secondary amplicon-based test on cfDNA. Clinical tests were performed on 422 pregnancies with or without abnormal ultrasound findings or family history. Follow-up studies on cases with available outcome results confirmed 20 true-positive, 127 true-negative, zero false-positive, and zero-false negative results. The initial clinical study demonstrated that this non-invasive test can provide valuable molecular information for the detection of a wide spectrum of dominant monogenic diseases, complementing current screening for aneuploidies or carrier screening for recessive disorders.
A non-invasive prenatal test utilizing cell-free DNA simultaneously detects mutations in 30 genes frequently associated with dominant monogenic diseases and demonstrates high accuracy in human clinical samples.
Journal Article
Genomic analysis of mycosis fungoides and Sézary syndrome identifies recurrent alterations in TNFR2
by
Khavari, Paul A
,
Armstrong, Randall
,
Kim, Youn
in
45/23
,
631/208/514/1948
,
692/699/67/1990/291
2015
Paul Khavari and colleagues report genomic analyses of cutaneous T cell lymphomas. They identify recurrent point mutations and genomic gains of
TNFRSF1B
, encoding the tumor necrosis factor receptor TNFR2, in 18% of tumors and show that expression of a recurrent TNFR2 mutant in T cells leads to enhanced non-canonical NF-κB signaling that is sensitive to the proteasome inhibitor bortezomib.
Mycosis fungoides and Sézary syndrome comprise the majority of cutaneous T cell lymphomas (CTCLs), disorders notable for their clinical heterogeneity that can present in skin or peripheral blood. Effective treatment options for CTCL are limited, and the genetic basis of these T cell lymphomas remains incompletely characterized
1
. Here we report recurrent point mutations and genomic gains of
TNFRSF1B
, encoding the tumor necrosis factor receptor TNFR2, in 18% of patients with mycosis fungoides and Sézary syndrome. Expression of the recurrent TNFR2 Thr377Ile mutant in T cells leads to enhanced non-canonical NF-κB signaling that is sensitive to the proteasome inhibitor bortezomib. Using an integrative genomic approach, we additionally discovered a recurrent
CTLA4
-
CD28
fusion, as well as mutations in downstream signaling mediators of these receptors.
Journal Article
TBX6 Null Variants and a Common Hypomorphic Allele in Congenital Scoliosis
by
Zhang, Jian
,
Qiu, Guixing
,
Cheung, Sau Wai
in
Adolescent
,
Alleles
,
Asian Continental Ancestry Group - genetics
2015
Little is known about the causes of scoliosis. The authors found that mutant TBX6, a transcription factor, caused congenital scoliosis in approximately 10% of the affected Han Chinese persons evaluated. It is also a cause of scoliosis in persons of other ancestries.
Congenital scoliosis, a form of vertebral malformation, has an estimated prevalence of approximately 1 in 2000 live births.
1
It is manifested as a lateral curvature of the spine exceeding 10 degrees and results from defects in vertebra formation during embryogenesis.
2
,
3
Previous evidence in animal models suggested that genetic factors contribute to vertebral malformations.
3
,
4
Genetic mutations have been implicated in human congenital scoliosis, but their low penetrance highlights the complex molecular basis of the disorder and hinders molecular diagnosis of and genetic counseling for congenital scoliosis.
4
,
5
The proximal 16p11.2 deletion in humans is rare but recurrent, with a . . .
Journal Article
Best practices for the analytical validation of clinical whole-genome sequencing intended for the diagnosis of germline disease
by
Stavropoulos, Dimitri J
,
Klee, Eric W
,
Belmont, John W
in
Genetic disorders
,
Genomes
,
Whole genome sequencing
2020
Whole-genome sequencing (WGS) has shown promise in becoming a first-tier diagnostic test for patients with rare genetic disorders; however, standards addressing the definition and deployment practice of a best-in-class test are lacking. To address these gaps, the Medical Genome Initiative, a consortium of leading healthcare and research organizations in the US and Canada, was formed to expand access to high-quality clinical WGS by publishing best practices. Here, we present consensus recommendations on clinical WGS analytical validation for the diagnosis of individuals with suspected germline disease with a focus on test development, upfront considerations for test design, test validation practices, and metrics to monitor test performance. This work also provides insight into the current state of WGS testing at each member institution, including the utilization of reference and other standards across sites. Importantly, members of this initiative strongly believe that clinical WGS is an appropriate first-tier test for patients with rare genetic disorders, and at minimum is ready to replace chromosomal microarray analysis and whole-exome sequencing. The recommendations presented here should reduce the burden on laboratories introducing WGS into clinical practice, and support safe and effective WGS testing for diagnosis of germline disease.
Journal Article
The Medical Genome Initiative: moving whole-genome sequencing for rare disease diagnosis to the clinic
by
Kearney, Hutton M.
,
Bick, David
,
Belmont, John W.
in
Best practice
,
Bioinformatics
,
Biomedical and Life Sciences
2020
Clinical whole-genome sequencing (WGS) offers clear diagnostic benefits for patients with rare disease. However, there are barriers to its widespread adoption, including a lack of standards for clinical practice. The Medical Genome Initiative consortium was formed to provide practical guidance and support the development of standards for the use of clinical WGS.
Journal Article
Dosage Effects of Cohesin Regulatory Factor PDS5 on Mammalian Development: Implications for Cohesinopathies
2009
Cornelia de Lange syndrome (CdLS), a disorder caused by mutations in cohesion proteins, is characterized by multisystem developmental abnormalities. PDS5, a cohesion protein, is important for proper chromosome segregation in lower organisms and has two homologues in vertebrates (PDS5A and PDS5B). Pds5B mutant mice have developmental abnormalities resembling CdLS; however the role of Pds5A in mammals and the association of PDS5 proteins with CdLS are unknown. To delineate genetic interactions between Pds5A and Pds5B and explore mechanisms underlying phenotypic variability, we generated Pds5A-deficient mice. Curiously, these mice exhibit multiple abnormalities that were previously observed in Pds5B-deficient mice, including cleft palate, skeletal patterning defects, growth retardation, congenital heart defects and delayed migration of enteric neuron precursors. They also frequently display renal agenesis, an abnormality not observed in Pds5B(-/-) mice. While Pds5A(-/-) and Pds5B(-/-) mice die at birth, embryos harboring 3 mutant Pds5 alleles die between E11.5 and E12.5 most likely of heart failure, indicating that total Pds5 gene dosage is critical for normal development. In addition, characterization of these compound homozygous-heterozygous mice revealed a severe abnormality in lens formation that does not occur in either Pds5A(-/-) or Pds5B(-/-) mice. We further identified a functional missense mutation (R1292Q) in the PDS5B DNA-binding domain in a familial case of CdLS, in which affected individuals also develop megacolon. This study shows that PDS5A and PDS5B functions other than those involving chromosomal dynamics are important for normal development, highlights the sensitivity of key developmental processes on PDS5 signaling, and provides mechanistic insights into how PDS5 mutations may lead to CdLS.
Journal Article
Evidence review and considerations for use of first line genome sequencing to diagnose rare genetic disorders
by
Wigby, Kristen M
,
Taylor, Stacie L
,
Kulkarni, Shashikant
in
Genetic disorders
,
Genetic screening
,
Genomes
2024
Early use of genome sequencing (GS) in the diagnostic odyssey can reduce suffering and improve care, but questions remain about which patient populations are most amenable to GS as a first-line diagnostic test. To address this, the Medical Genome Initiative conducted a literature review to identify appropriate clinical indications for GS. Studies published from January 2011 to August 2022 that reported on the diagnostic yield (DY) or clinical utility of GS were included. An exploratory meta-analysis using a random effects model evaluated DY based on cohort size and diagnosed cases per cohort. Seventy-one studies met inclusion criteria, comprising over 13,000 patients who received GS in one of the following settings: hospitalized pediatric patients, pediatric outpatients, adult outpatients, or mixed. GS was the first-line test in 38% (27/71). The unweighted mean DY of first-line GS was 45% (12–73%), 33% (6–86%) in cohorts with prior genetic testing, and 33% (9–60%) in exome-negative cohorts. Clinical utility was reported in 81% of first-line GS studies in hospitalized pediatric patients. Changes in management varied by cohort and underlying molecular diagnosis (24–100%). To develop evidence-informed points to consider, the quality of all 71 studies was assessed using modified American College of Radiology (ACR) criteria, with five core points to consider developed, including recommendations for use of GS in the N/PICU, in lieu of sequential testing and when disorders with substantial allelic heterogeneity are suspected. Future large and controlled studies in the pediatric and adult populations may support further refinement of these recommendations.
Journal Article
Variable thickness approach for finding minimum laminate thickness and investigating effect of different design variables on its performance
by
Tripathi, Vipin Kumar
,
Kulkarni, Nishant Shashikant
in
Design
,
Design optimization
,
Genetic algorithms
2018
The performance of majority engineering systems made of composite laminates can be improved by increasing strength to weight ratio. Variable thickness approach (VTA), in discrete form, used in this study is capable of finding minimum laminate thickness in one stage only, instead of two stage methodology defined by other researchers, with substantial accuracy for the given load conditions. This minimum required laminate thickness can be used by designers in multiple ways. Current study reveals that effectiveness of VTA in this regard depends on ply thickness increment value and number of plies. Maximum Stress theory, Tsai Wu theory and Tsai Hill theory are used as constraints, while ply angles, ply thicknesses and number of plies in discrete form are used as design variables in current simulation studies. Optimization is carried out using direct value coded genetic algorithm. The effect of design variables such as ply angles, ply thicknesses and number of plies in discrete form on optimum solution is investigated considering Uniform Thickness Approach (UTA) and Variable Thickness Approach (VTA) for various load cases.
Journal Article