This paper applies objective methods to explore the technological origins of the widely acclaimed CRISPR breakthrough in the technological domain of genome engineering. Previously developed patent ...search techniques are first used to recover a set of patents that well-represent the genome editing domain before CRISPR. Main paths are then determined from the citation network associated with this patent set allowing identification of the three major knowledge trajectories. The most significant of these trajectories for CRISPR involves the core of genome editing with less significant trajectories involving cloning and endonuclease specific developments. The major patents on the core trajectory are consistent with qualitative expert knowledge of the topical area. A second set of patents that we call the CRISPR roots are obtained by finding the patents directly cited by the recent CRISPR patents along with patents cited by that set of patents. We find that the CRISPR roots contain 8 key patents from the genome engineering main path associated with restriction endonucleases and the expected strong connection of CRISPR to prior genome editing technology such as Zn finger nucleases. Nonetheless, analysis of the full CRISPR roots shows that a very wide array of technological knowledge beyond genome engineering has contributed to achieving the CRISPR breakthrough. Such breadth in origins is not surprising since "spillover" is generally perceived as important and previous qualitative studies of CRISPR have shown not only technological breadth in origins but scientific breadth as well. In addition, we find that the estimated rate of functional performance improvement of the CRISPR roots set is about 9% per year compared to the genome engineering set (~4% per year). These estimates indicate below average rates of improvement and may indicate that CRISPR (and perhaps yet undiscovered) genome engineering developments could evolve in effectiveness over an upcoming long rather than short time period.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this work we summarize our understanding of melanocortin 4 receptor (MC4R) pathway activation, aiming to define a safe and effective therapeutic targeting strategy for the MC4R. Delineation of ...cellular MC4R pathways has provided evidence for distinct MC4R signaling events characterized by unique receptor activation kinetics. While these studies remain narrow in scope, and have largely been explored with peptidic agonists, the results provide a possible correlation between distinct ligand groups and differential MC4R activation kinetics. In addition, when a set of small-molecule and peptide MC4R agonists are compared, evidence of biased signaling has been reported. The results of such mechanistic studies are discussed.
Increasing evidence points toward epigenetic variants as a risk factor for developing obesity. We analyzed DNA methylation of the
(pro-opiomelanocortin) gene, which is pivotal for satiety regulation. ...We identified sex-specific and nongenetically determined
hypermethylation associated with a 1.4-fold (confidence interval, 1.03 to 2.04) increased individual risk of developing obesity. To investigate the early embryonic establishment of
methylation states, we established a human embryonic stem cell (hESC) model. Here, hESCs (WA01) were transferred into a naïve state, which was associated with a reduction of DNA methylation. Naïve hESCs were differentiated via a formative state into POMC-expressing hypothalamic neurons, which was accompanied by re-establishment of DNA methylation patterning. We observed that reduced
gene expression was associated with increased
methylation in
-expressing neurons. On the basis of these findings, we treated
-hypermethylated obese individuals (
= 5) with an MC4R agonist and observed a body weight reduction of 4.66 ± 2.16% (means ± SD) over a mean treatment duration of 38.4 ± 26.0 weeks. In summary, we identified an epigenetic obesity risk variant at the
gene fulfilling the criteria for a metastable epiallele established in early embryonic development that may be addressable by MC4R agonist treatment to reduce body weight.
Background: Genetic testing can improve the diagnosis of rare genetic diseases of obesity and identify patients who may benefit from targeted therapy. Patients with genetic variants in the ...melanocortin-4 receptor (MC4R) pathway may present with severe, early-onset obesity and hyperphagia. Historically, genetic testing in patients with obesity has been limited. The Uncovering Rare Obesity® testing program aims to enhance access to genetic testing for these patients. The frequency of rare genetic variants in this population is currently unknown. Methods: We sequenced 16,061 individuals with severe, early-onset obesity as part of the US-based Uncovering Rare Obesity® genetic testing program. Genes include those with well-established associations with obesity, as well as genes associated with the MC4R pathway. We sequenced 8,230 individuals for 40 genes, and recently expanded the panel to include an additional 39 genes and 16p11.2 chromosomal region; 7,831 individuals have been sequenced on the broader panel. Yield estimates were weighted by the number of individuals sequenced for each gene. Results: Based on the expanded 79-gene panel, 18.6% of sequenced individuals had variants that may qualify them for commercial or investigational treatment with the MC4R agonist setmelanotide. An additional 46.2% of individuals had variants not currently eligible for setmelanotide, but that may support a genetic diagnosis of obesity. Conclusions: In this cohort of individuals with severe, early-onset obesity, ~65% carried potentially actionable variants. As additional data become available about the investigational genes and obesity, and as new obesity-related genes are identified, these estimates may change. Genetic testing of patients with severe obesity, particularly those with a history of early-onset obesity suggestive of a potential genetic origin, may therefore be an important component of understanding the etiology of these patients' phenotypes, and could potentially impact the course of care for these patients.
Background: Bardet-Biedl and Alström syndromes (BBS/AS) are rare, autosomal recessive diseases that often lead to early-onset obesity and hyperphagia. Both BBS and AS are diagnosed based on clinical ...features, which may include early-onset obesity, early-onset diabetes, cardiomyopathy, hyperphagia, visual impairment, polydactyly, renal anomalies, and cognitive impairment. More than 20 genes are associated with BBS/AS, but little is known about the frequency of variants in these genes in a population with early-onset, severe obesity, irrespective of clinical features. Methods: We sequenced 22 BBS genes and ALMS1 as part of the Uncovering Rare Obesity genetic testing program in 13,857 individuals with severe obesity (<18 years old, >97th percentile BMI for age; >18 years old, BMI >40kg/m2). Variants were classified according to ACMG criteria as pathogenic/likely pathogenic (P/LP) or as variants of uncertain significance (VUS). Individuals were determined to be biallelic (>2 alleles in 1 gene), heterozygous (1 allele in only 1 gene), or composite heterozygous (1 allele per gene in multiple BBS genes). Results: In this cohort, 1.77% of individuals carried biallelic variants in BBS genes (1.13%) or ALMS1 (0.64%), including 0.33% with >2 P/LP alleles (BBS, 0.30%; ALMS1, 0.03%). It is unknown whether patients were sequenced because of suspected BBS/AS, and data are not available on related clinical characteristics, other than their severe early-onset obesity. Conclusions: In our cohort of >13,000 individuals with early-onset obesity, 1.8% were biallelic for variants in BBS genes or ALMS1. BBS/AS are heterogenous diseases that present with a variety of symptoms that evolve over time, and more research is needed to determine whether identification of individuals with biallelic variants may help identify patients in need of follow-up support regarding BBS/AS diagnosis. Today, these diseases are diagnosed based on clinical features, and genetic testing may help provide additional evidence to support a diagnosis.
With an ever-increasing resource of validated single-nucleotide polymorphisms (SNPs), the limiting factors in genome-wide association analysis have become genotyping capacity and the availability of ...DNA. We provide a proof of concept of the use of pooled DNA as a means of efficiently screening SNPs and prioritizing them for further study. This approach reduces the final number of SNPs that undergo full, sample-by-sample genotyping as well as the quantity of DNA used overall. We have examined 15 SNPs in the cholesteryl ester transfer protein (CETP) gene, a gene previously demonstrated to be associated with serum high-density lipoprotein cholesterol levels. The SNPs were amplified in two pools of DNA derived from groups of individuals with extremely high and extremely low serum high-density lipoprotein cholesterol levels, respectively. P values <0.05 were obtained for 14 SNPs, supporting the described association. Genotyping of the individual samples showed that the average margin of error in frequency estimate was ≈4% when pools were used. These findings clearly demonstrate the potential of pooling techniques and their associated technologies as an initial screen in the search for genetic associations.
Genetic Variation as a Guide to Drug Development Kleyn, Patrick W.; Vesell, Elliot S.
Science (American Association for the Advancement of Science),
09/1998, Letnik:
281, Številka:
5384
Journal Article
Recenzirano
Kleyn and Vesell discuss pharmacogenetics, which is the study of genetic variation underlying differential response to drugs.
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