Abstract
The advent of the knowledge on human genetics, by the identification of disease-associated variants, culminated in the understanding of human variability. With the genetic knowledge, the specificity of the clinical phenotype and the drug response of each individual were understood. Using the cystic fibrosis (CF) as an example, the new terms that emerged such as personalized medicine and precision medicine can be characterized. The genetic knowledge in CF is broad and the presence of a monogenic disease caused by mutations in the CFTR gene enables the phenotype–genotype association studies (including the response to drugs), considering the wide clinical and laboratory spectrum dependent on the mutual action of genotype, environment, and lifestyle. Regarding the CF disease, personalized medicine is the treatment directed at the symptoms, and this treatment is adjusted depending on the patient’s phenotype. However, more recently, the term precision medicine began to be widely used, although its correct application and understanding are still vague and poorly characterized. In precision medicine, we understand the individual as a response to the interrelation between environment, lifestyle, and genetic factors, which enabled the advent of new therapeutic models, such as conventional drugs adjustment by individual patient dosage and drug type and response, development of new drugs (read through, broker, enhancer, stabilizer, and amplifier compounds), genome editing by homologous recombination, zinc finger nucleases, TALEN (transcription activator-like effector nuclease), CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats-CRISPR-associated endonuclease 9), and gene therapy. Thus, we introduced the terms personalized medicine and precision medicine based on the CF.
Introduction
Currently, numerous and significant advances have been achieved on the pathophysiological and genetic knowledge of numerous diseases. These advances are associated with the advent of new technologies related to diagnosis, treatment, and reduction of costs from genetic studies and implementation of new management approaches, resulting mainly from multicenter studies and meta-analyses. These studies have shown significant population variability and enabled the implementation of databases with numerous genetic variants, including mutations and polymorphisms (; Xu et al., 2016).
The importance of these skills to the internist, researchers, geneticist, and other health professionals is that, increasingly, every disease is demonstrated as a complex of many diseases, regarding the symptoms, divided into numerous genotypes, phenotypes, and endotypes (Figure 1).
FIGURE 1
The genetic part that characterizes the diseases has been demonstrated in numerous studies, even in diseases that are true public health problems, such as asthma and tuberculosis, among the diseases of the respiratory tract. With the increase of genetic knowledge, it is essential to analyze the cost-benefit, cost-effectiveness, and cost-utility (Scott, 2016), application of ethical rigor necessary to identify mutations and variants in diagnostic and screening tests, especially considering the pediatric age group and the amount of information that can be generated with collection of genetic material and its laboratory analysis, as well as its application ().
In the study of genetic variants, the determination of genes, their polymorphisms and mutations, which are associated with certain diseases, and their variability is constant, including the CF (OMIM: #219700). In recent decades, the implementation of genetic knowledge on CF occurred, mostly, by obtaining and using new methods to identify genetic variants (Ziętkiewicz et al., 2014; ; ; ; Straniero et al., 2016; Ratkiewicz et al., 2017).
Cystic Fibrosis Disease
The CF is a monogenic, autosomal, and recessive disease, with highly variable and complex clinical expression that had the identification of its causal gene in 1989, the known CFTR gene in chromosome 7q31.2 (CFTR) (; ). From that date, numerous studies have been published and led to the identification of approximately 2,000 mutations, only in that gene (Cystic Fibrosis Mutation Database, accessed on 05/01/2017). The CF diagnosis and diversity according to the CFTR mutation status can be observed in Figure 2.
FIGURE 2
The clinical manifestations in CF are complex, and even decades after the description of the disease and identification of the CFTR gene, not every spectrum of the disease is known or even understood, including the interaction between socioeconomic status and health outcomes (
In CF, as well as in other diseases, the genetic knowledge involved determines the causal basis of the disease, provides the genetic counseling and the possibility of understanding the clinical variability (phenotypes and endotypes), as well as the response to the treatment and new therapeutic modalities. In recent years, CF has been a model for numerous studies (approximately 45,000 publications in PubMed), and, in most of them, genetics and management go hand in hand (
On the other hand, based on the knowledge gained from the molecular study, the implementation of the personalized medicine occurred, mainly, for the new read-through drugs, enhancers, CFTR protein stabilizers and amplifier compounds (
Personalized Medicine – the Example of Cystic Fibrosis
Personalized medicine is a term used for the treatment focusing on the patients based on their individual clinical characterization, considering the diversity of symptoms, severity, and genetic traits. Thus, personalized medicine is performed in CF, and in many other diseases, based on the patients’ symptoms. A classic example is the use of supplementation of digestive enzymes in CF. The dose is adjusted, not only because of the patient’s physiological characteristics, but considering the response to the enzyme, volume of food ingested, type of food ingested, number of meals, body mass gain, growth rate, and type of enzyme used (
However, today, perspectives and directions have been questioned and implemented to seek mechanisms to treat the disease and not the clinical signs and symptoms. In the case of pulmonary disease in CF, the signs and symptoms caused by the gravity associated with chronic inflammation and infection of lungs with resistance to antibiotics, progressive during the patients’ lives, is a condition that requires further study (Rutter et al., 2016; Samson et al., 2016).
Thus, we cannot characterize the personalized medicine as the medicine of the genomic era, but as the medicine that aims to treat the particularities of patients, often disregarding or simplifying the genetic nuances.
Precision Medicine – an Innovation that Emerged
Overlapping the personalized medicine or a more complex model of understanding the phenotypic presentation, in 2015, the term precision medicine began to be used. The father of the precision medicine is researcher Archibald E. Garrod (1857–1936), who described the ubiquity of the individual variation, both in cases of diseases and in the identification of the human variability (Perlman and Govindaraju, 2016).
In precision medicine, the molecular information maximizes the accuracy with which the patients are categorized and treated, i.e., we have an endotype (or phenotypic variant) of a disease, which comes from a gene or group of genes and their interaction with the environmental factor and lifestyle (Perlman and Govindaraju, 2016) (Figure 1). In CF, we have multiple gravity phenotypes and clinical manifestations that are described and come from complex interactions between mutations in the CFTR gene, modifier genes, environment, and lifestyle (
Among the concepts and definitions of precision medicine we have three aspects that must be considered: (i) traditional medicine should not be denied and must be recognized as the basis of precision medicine; (ii) precision medicine is not equal to simple convergence of new technologies – the relevant information for genomic knowledge requires effective integration with classical genetics, metabolomics, and clinical phenotypes (including symptoms and clinical signs, biochemical markers, and image and pathological characteristics, among others) to compose an individual and complete biological database, and contribute to diagnosis and treatment that are based on the patient’s individuality; (iii) precision medicine is not equal to a simple and individualized drug, but a medicine that combines standardization and individualization (Wang et al., 2016).
On the other hand, the implementation of precision medicine presents barriers that need to be overcome, such as: (i) regulation by governmental and medical entities, including the use of new ethical regulations; (ii) high cost for its implementation and for the pharmacological treatments obtained from the knowledge acquired; (iii) how to use and disclose information appropriately; (iv) how to approach and direct what will be done with patients who are part of the research projects before the status of the Government, the pharmaceutical industry and expectations of patients and/or family members; (v) analysis of bioinformatics that is still limited; (vi) the computational data analysis system needs to be better implemented; (vii) construction of prediction and interaction programs for clinical, laboratory, and genetic evaluation; (viii) large-scale sequencing, as well as punctual, also not available to all individuals who may benefit from the future of precision medicine (
Precision medicine, despite the use of complex techniques and data analysis, still follows the analysis model of reconstruction, based on the reductionist theory, showing difficulty in understanding the adaptive degree of the body regarding change, as well as the quest to control the precision of the method applied. Thus, we should seek a model to study and apply precision medicine at the holistic level, which is a barrier we will have to overcome for greater development in the application of the theory in the next years (Yuan, 2016).
Precision Medicine – the Example of Cystic Fibrosis
Cystic fibrosis is one of the most important examples to describe the precision medicine. However, the problems found in CF for precision medicine treatment are complex to be solved, although CF is a monogenic disease. However, when dealing with other diseases, such as asthma, which is complex – resulting from the interaction of the environment with multiple genes (polygenic): each gene determines a small fraction in response to the drug used – the use of complete and complex tools that determine metabolic networks for polygenic modulation must be implemented and enables the use of precision medicine (
Researchers on CF offered us the publication of numerous studies, which enabled new prospects for the treatment of the disease, especially the pulmonary disease, with studies focusing on precision medicine (
Despite the numerous studies on CF, there are still doubts about the applicability of precision medicine, then called personalized medicine, when we considered the read-through drugs, enhancers, stabilizers, and amplifiers (
In CF, models of the CFTR molecular dynamics enabled the understanding of the interaction between the different effectors of the metabolic pathway that composes the CFTR protein expression and the evolution in the treatment and knowledge of the new drugs (
However, regardless of the precision or traditional medicine, we have to be aware of and participate in a holistic medicine, directed to the patient, not to the disease itself. It must be considered that various drugs interact with one another and with the body, and that we must seek the best way to achieve the balance between the individual and a good response to the treatment, maintaining and/or improving the quality and expectation of life (
Studies on CF can be a source of knowledge about the treatment of other diseases, especially of chronic obstructive pulmonary diseases. One of these models can be assessed as to the response of drugs used in CF and also in other respiratory diseases, such as inhaled antibiotics, which has had its response evaluated in the personalized/precision medicine (
Studies of common phenotypes, particularly of clinical manifestations, of different diseases, allow knowledge development and cost reduction for precision medicine, and some of these studies are conducted in diseases with pulmonary phenotypes (Priyadharshini and Teran, 2016).
In addition to the drugs available by traditional and precision medicine, aforementioned, we have the possibility of gene therapy (which has as main barrier the layer of mucus in the lungs, preventing the transferring of genetic material) (
All the information obtained from genetic studies has lead to the realization of a dream, which is the implementation of precision medicine in the healthcare network (
Basic understanding of precision medicine and of the techniques employed, mainly in the area of genetics, will be extremely necessary for physicians, regardless of their specialty, as we advance quickly toward the genomics and precision medicine era. Based on a monogenic disease, such as the CF, we can describe the concepts of personalized medicine and precision medicine and aid in the dissemination and in the possibility of using personalized medicine and precision medicine.
In short, we simply described the aspects and concepts involved in both personalized and precision medicine, as well as the therapeutic possibilities that have emerged in CF by the knowledge of precision medicine. The data presented can be briefly observed in Figure 1, where there is characterization of the flowchart regarding CF variability and conceptualization of personalized medicine and precision medicine. Moreover, Figure 2 shows an example regarding the clinical and laboratory response achieved with the introduction of personalized medicine and precision medicine and, in addition, we include a short flowchart regarding CF diagnosis, CFTR gene, and CFTR mutation classes.
Future and Challenges in Personalized Medicine and Precision Medicine
Currently we have the availability of techniques for molecular analysis of numerous diseases. However, the development of drugs for various disorders is lacking, and in some cases (i.e., CF) in which the drug exists, there is lack of therapeutic efficacy. Another limiting factor is the high cost related to the diagnosis and application of precision medicine drugs. We must also consider the need to expand medical education for the new era of genetics, with broad knowledge of human genetic diversity and applicability in the treatment and follow-up of various diseases, including the CF disease.
Conclusion
In recent years, many advances have been made in medical genetics, which led to the development of personalized medicine and precision medicine, making real a dream of many researchers, family members, and patients.
Personalized medicine is the treatment directed to the symptoms, and this treatment is adjusted depending on the patient’s phenotype. However, more recently, the term precision medicine began to be widely used although its correct application and understanding are still vague and poorly characterized. In precision medicine, we understand the individual as a response to the interrelation between environment, lifestyle, and genetic factors, which enabled the advent of new therapeutic models, such as conventional drugs adjustment by individual patient dosage and drug type and response, new drugs development (read through, broker, enhancer, stabilizer and amplifier compounds),genome editing by homologous recombination, zinc finger nucleases, TALEN, CRISPR-Cas9, and gene therapy. Thus, this mini review introduced the terms personalized medicine and precision medicine based on the CF.
Many of the problems related to the implementation of precision medicine could be solved with initiatives such as the BIPMed, which gathers members of five CEPIDs (Centers of Research, Innovation, and Dissemination) supported by the FAPESP (São Paulo Research Foundation). The BIPMed is the first public genomic database in Latin America1 and has been successful in adding data from healthy individuals that could contribute in future studies of precision medicine.
Statements
Author contributions
FM was responsible for gathering bibliographic data, writing the draft, editing, and submitting the article to the journal. CB and JR revised the manuscript, made a critical revision, and gave the approval for the final submission.
Funding
FM: São Paulo Research Foundation (FAPESP) in the research support and fellowship grants numbers #2011/12939-4; #2015/12183-8, and #2015/12858-5; Fund for the Support to Education, Research, and Extension of the University of Campinas, grant number #0648/2015; JR: FAPESP, grant number #2011/18845-1 and #2015/12183-8.
Acknowledgments
We thank Luciana Montes Rezende, Luciana Cardoso Bonadia, Stephanie Villa-Nova Pereira, Maria Ângela Gonçalves de Oliveira Ribeiro, Maria de Fátima Corrêa Pimenta Servidoni, Carlos Emílio Levy, Adressa Oliveira Peixoto, Adyléia Aparecida Contrera Dalbo Toro, Renan Mauch, Roberto José Negrão Nogueira, Eulália Sakano, Antônio Fernando Ribeiro, Natasha Matsunaga, Alfonso Eduardo Alvarez, Carla Cristina de Souza Gomez, Elizete Aparecida Lomazi, Paloma Lopes Francisco Parazzi, Larissa Furlan, Emília Gonçalves, Aline Gonçalves, Milena Baptistella Grotta Silva, and Alethea Faria, who presently contribute for the studies on cystic fibrosis at our reference center. We thank Espaço da Escrita/Coordenadoria Geral da Universidade – Unicamp – for providing the manuscript translation.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Abbreviations
- BIPMed
Brazilian Initiative on Precision Medicine
- CEPID
Centros de Pesquisa, Inovação e Difusão
- CF
cystic fibrosis
- CFTR
cystic fibrosis transmembrane regulator
- CRISPR-Cas9
clustered regularly interspaced short palindromic repeats-CRISPR-associated endonuclease 9
- FAPESP
Fundação de Amparo à Pesquisa do Estado de São Paulo
- OMIM
Online Mendelian Inheritance in Man
- TALEN
transcription activator-like effector nuclease
Footnotes
References
1
AlapatiD.MorriseyE. E. (2016). Gene editing and genetic lung disease: basic research meets therapeutic application.Am. J. Respir. Cell Mol. Biol.10.1165/rcmb.2016-0301PS[Epub ahead of print].
2
AltonE. W.BoydA. C.DaviesJ. C.GillD. R.GriesenbachU.HarrisonP. T.et al (2016). Genetic medicines for CF: Hype versus reality.Pediatr. Pulmonol.51S5–S17. 10.1002/ppul.23543
3
BakerM. W.AtkinsA. E.CordovadoS. K.HendrixM.EarleyM. C.FarrellP. M. (2016). Improving newborn screening for cystic fibrosis using next-generation sequencing technology: a technical feasibility study.Genet. Med.18231–238. 10.1038/gim.2014.209
4
Balfour-LynnI. M. (2014). Personalised medicine in cystic fibrosis is unaffordable.Paediatr. Respir. Rev.152–5. 10.1016/j.prrv.2014.04.003
5
BellecJ.BacchettaM.LosaD.AnegonI.ChansonM.NguyenT. H. (2015). CFTR inactivation by lentiviral vector-mediated RNA interference and CRISPR-Cas9 genome editing in human airway epithelial cells.Curr. Gene Ther.15447–459. 10.2174/1566523215666150812115939
6
BiancoA. M.MarcuzziA.ZaninV.GirardelliM.VuchJ.CrovellaS. (2013). Database tools in genetic diseases research.Genomics10175–85. 10.1016/j.ygeno.2012.11.001
7
BianeC.DelaplaceF.KlaudelH. (2016). Networks and games for precision medicine.Biosystems15052–60. 10.1016/j.biosystems.2016.08.006
8
BillerJ. A. (2015). Inhaled antibiotics: the new era of personalized medicine?Curr. Opin. Pulm. Med.21596–601. 10.1097/MCP.0000000000000216
9
BiltonD. (2014). Personalised medicine in cystic fibrosis must be made affordable.Paediatr. Respir. Rev.156–7. 10.1016/j.prrv.2014.04.004
10
BotkinJ. R. (2016). Ethical issues in pediatric genetic testing and screening.Curr. Opin. Pediatr.28700–704.
11
BoyleM. P.BellS. C.KonstanM. W.McColleyS. A.RoweS. M.RietschelE.et al (2014). A CFTR corrector (lumacaftor) and a CFTR potentiator (ivacaftor) for treatment of patients with cystic fibrosis who have a phe508del CFTR mutation: a phase 2 randomised controlled trial.Lancet Respir. Med.2527–538. 10.1016/S2213-2600(14)70132-8
12
BoyleM. P.De BoeckK. (2013). A new era in the treatment of cystic fibrosis: correction of the underlying CFTR defect.Lancet Respir. Med.1158–163. 10.1016/S2213-2600(12)70057-7
13
BreckenridgeA.EichlerH. G.JarowJ. P. (2016). Precision medicine and the changing role of regulatory agencies.Nat. Rev. Drug. Discov.15805–806. 10.1038/nrd.2016.206
14
BrownS. D.WhiteR.TobinP. (2017). Keep them breathing: cystic fibrosis pathophysiology, diagnosis, and treatment.JAAPA3023–27. 10.1097/01.JAA.0000515540.36581.92
15
CallebautI.HoffmannB.LehnP.MornonJ. P. (2016). Molecular modelling and molecular dynamics of CFTR.Cell. Mol. Life Sci.743–22. 10.1007/s00018-016-2385-9
16
CamarasaM. V.GálvezV. M. (2016). Robust method for TALEN-edited correction of pF508del in patient-specific induced pluripotent stem cells.Stem Cell Res. Ther.726. 10.1186/s13287-016-0275-6
17
CastellaniC.AssaelB. M. (2016). Cystic fibrosis: a clinical view. Cystic fibrosis: a clinical view.Cell. Mol. Life Sci.74129–140. 10.1007/s00018-016-2393-9
18
ChangE. H.ZabnerJ. (2015). Precision genomic medicine in cystic fibrosis.Clin. Transl. Sci.8606–610. 10.1111/cts.12292
19
CooneyL.Abou AlaiwaM. H.ShahV. S.BouzekD. C.StroikM. R.PowersL. S.et al (2016). Lentiviral-mediated phenotypic correction of cystic fibrosis pigs.JCI Insight1e88730. 10.1172/jci.insight.88730
20
CorvolH.ThompsonK. E.TabaryO.le RouzicP.GuillotL. (2016). Translating the genetics of cystic fibrosis to personalized medicine.Transl. Res.16840–49. 10.1016/j.trsl.2015.04.008
21
DaviesJ. C. (2015). The future of CFTR modulating therapies for cystic fibrosis.Curr. Opin. Pulm. Med.21579–584. 10.1097/MCP.0000000000000211
22
De BoeckK.AmaralM. D. (2016). Progress in therapies for cystic fibrosis.Lancet. Respir. Med.4662–674. 10.1016/S2213-2600(16)00023-0
23
DuncanG. A.JungJ.HanesJ.SukJ. S. (2016). The mucus barrier to inhaled gene therapy.Mol. Ther.242043–2053. 10.1038/mt.2016.182
24
DzauV. J.GinsburgG. S. (2016). Realizing the full potential of precision medicine in health and health care.JAMA3161659–1660. 10.1001/jama.2016.14117
25
FarrellP. M.WhiteT. B.RenC. L.HempsteadS. E.AccursoF.DerichsN.et al (2017). Diagnosis of cystic fibrosis: consensus guidelines from the cystic fibrosis foundation.J. Pediatr.181SS4–S15.e1. 10.1016/j.jpeds.2016.09.064
26
FerkolT.QuintonP. (2015). Precision medicine: at what price?Am. J. Respir. Crit. Care Med.192658–659. 10.1164/rccm.201507-1428ED
27
GreenD. M. (2013). Cystic fibrosis: a model for personalized genetic medicine.N C Med. J.74486–487.
28
GriesenbachU.DaviesJ. C.AltonE. (2016). Cystic fibrosis gene therapy: a mutation-independent treatment.Curr. Opin. Pulm. Med.22602–609. 10.1097/MCP.0000000000000327
29
GuoW.JiY.CatenacciD. V. (2016). A subgroup cluster-based Bayesian adaptive design for precision medicine.Biometrics10.1111/biom.12613[Epub ahead of print].
30
IkpaP. T.BijveldsM. J.de JongeH. R. (2014). Cystic fibrosis: toward personalized therapies.Int. J. Biochem. Cell. Biol.52192–200. 10.1016/j.biocel.2014.02.008
31
JordanC. L.NoahT. L.HenryM. M. (2016). Therapeutic challenges posed by critical drug-drug interactions in cystic fibrosis.Pediatr. Pulmonol.51S61–S70. 10.1002/ppul.23505
32
KerstenE. T.KoppelmanG. H. (2016). Pharmacogenetics of asthma: toward precision medicine.Curr. Opin. Pulm. Med.2312–20. 10.1097/MCP.0000000000000335
33
LiangF.ShangH.JordanN. J.WongE.MercadanteD.SaltzJ.et al (2017). High-throughput screening for readthrough modulators of CFTR PTC mutations.SLAS Technol.22315–324. 10.1177/2472630317692561
34
LimR. M.SilverA. J.SilverM. J.BorrotoC.SpurrierB.PetrossianT. C.et al (2016). Targeted mutation screening panels expose systematic population bias in detection of cystic fibrosis risk.Genet. Med.18174–179. 10.1038/gim.2015.52
35
Lopes-PachecoM. (2016). CFTR modulators: shedding light on precision medicine for cystic fibrosis.Front. Pharmacol.7:275. 10.3389/fphar.2016.00275
36
LundmanE.GaupH. J.BakkeheimE.OlafsdottirE. J.RootweltT.StorrøstenO. T.et al (2016). Implementation of newborn screening for cystic fibrosis in Norway. Results from the first three years.J. Cyst. Fibros.15318–324. 10.1016/j.jcf.2015.12.017
37
MarsonF. A. L.BertuzzoC. S.RibeiroJ. D. (2015). Personalized drug therapy in cystic fibrosis: from fiction to reality.Curr. Drug Targets161007–1017. 10.2174/1389450115666141128121118
38
MarsonF. A. L.BertuzzoC. S.RibeiroJ. D. (2016). Classification of CFTR mutation classes.Lancet Respir. Med.4e37–e38. 10.1016/S2213-2600(16)30188-6
39
MartinU. (2015). Pluripotent stem cells for disease modeling and drug screening: new perspectives for treatment of cystic fibrosis?Mol. Cell. Pediatr.215. 10.1186/s40348-015-0023-5
40
MartinianoS. L.SagelS. D.ZemanickE. T. (2016). Cystic fibrosis: a model system for precision medicine.Curr. Opin. Pediatr.28312–317. 10.1097/MOP.0000000000000351
41
MouH.BrazauskasK.RajagopalJ. (2015). Personalized medicine for cystic fibrosis: establishing human model systems.Pediatr. Pulmonol.50S14–S23. 10.1002/ppul.23233
42
OatesG. R.SchechterM. S. (2016). Socioeconomic status and health outcomes: cystic fibrosis as a model.Expert. Rev. Respir. Med.10967–977. 10.1080/17476348.2016.1196140
43
Ozen AlahdabY.DumanD. G. (2016). Pancreatic involvement in cystic fibrosis.Minerva Med.107427–436.
44
PankowS.BambergerC.CalzolariD.Martínez-BartoloméS.Lavallée-AdamM.BalchW. E.et al (2015). ΔF508 CFTR interactome remodelling promotes rescue of cystic fibrosis.Nature528510–516. 10.1038/nature15729
45
PerlmanR. L.GovindarajuD. R. (2016). Archibald E. Garrod: the father of precision medicine.Genet. Med.181088–1089. 10.1038/gim.2016.5
46
PratherR. S.LorsonM.RossJ. W.WhyteJ. J.WaltersE. (2013). Genetically engineered pig models for human diseases.Annu. Rev. Anim. Biosci.1203–219. 10.1146/annurev-animal-031412-103715
47
PriyadharshiniV. S.TeranL. M. (2016). Personalized medicine in respiratory disease: role of proteomics.Adv. Protein Chem. Struct. Biol.102115–146. 10.1016/bs.apcsb.2015.11.008
48
QuonB. S.WilcoxP. G. (2015). A new era of personalized medicine for cystic fibrosis - at last! Can.Respir. J.22257–260. 10.1155/2015/921712
49
RafeeqM. M.MuradH. A. S. (2017). Cystic fibrosis: current therapeutic targets and future approaches.J. Transl. Med.1584. 10.1186/s12967-017-1193-9
50
RamalingamS.AnnaluruN.KandavelouK.ChandrasegaranS. (2014). TALEN-mediated generation and genetic correction of disease-specific human induced pluripotent stem cells.Curr. Gene Ther.14461–472. 10.2174/1566523214666140918101725
51
RatkiewiczM.PastoreM.McCoyK. S.ThompsonR.HayesDJr.SheikhS. I. (2017). Role of CFTR mutation analysis in the diagnostic algorithm for cystic fibrosis.World J. Pediatr.13129–135. 10.1007/s12519-017-0015-8
52
RutterW. C.BurgessD. R.BurgessD. S. (2016). Increasing incidence of multidrug resistance among cystic fibrosis respiratory bacterial isolates.Microb. Drug Resist.2351–55. 10.1089/mdr.2016.0048
53
SamsonC.TamaletA.ThienH. V.TaytardJ.PerissonC.NathanN.et al (2016). Long-term effects of azithromycin in patients with cystic fibrosis.Respir. Med.1171–6. 10.1016/j.rmed.2016.05.025
54
SatheM. N.FreemanA. J. (2016). Gastrointestinal, pancreatic, and hepatobiliary manifestations of cystic fibrosis.Pediatr. Clin. North Am.63679–698. 10.1016/j.pcl.2016.04.008
55
SchmidtB. Z.HaafJ. B.LealT.NoelS. (2016). Cystic fibrosis transmembrane conductance regulator modulators in cystic fibrosis: current perspectives.Clin. Pharmacol.8127–140. 10.2147/CPAA.S100759
56
SchneiderE. K.Reyes-OrtegaF.LiJ.VelkovT. (2016). Can cystic fibrosis patients finally catch a breath with Orkambi?Clin. Pharmacol. Ther.101130–141. 10.1002/cpt.548
57
SchwankG.KooB. K.SasselliV.DekkersJ. F.HeoI.DemircanT.et al (2013). Functional repair of CFTR by CRISPR/Cas9 in intestinal stem cell organoids of cystic fibrosis patients.Cell Stem Cell13653–658. 10.1016/j.stem.2013.11.002
58
ScottA. R. (2016). Technology: read the instructions.Nature537S54–S56. 10.1038/537S54a
59
SpielbergD. R.ClancyJ. P. (2016). Cystic Fibrosis and its management through established and emerging therapies.Annu. Rev. Genomics Hum. Genet.17155–175. 10.1146/annurev-genom-090314-050024
60
SteinesB.DickeyD. D.BergenJ.ExcoffonK. J.WeinsteinJ. R.LiX.et al (2016). CFTR gene transfer with AAV improves early cystic fibrosis pig phenotypes.JCI Insight1e88728. 10.1172/jci.insight.88728
61
StranieroL.SoldàG.CostantinoL.SeiaM.MelottiP.ColomboC.et al (2016). Whole-gene CFTR sequencing combined with digital RT-PCR improves genetic diagnosis of cystic fibrosis.J. Hum. Genet.61977–984. 10.1038/jhg.2016.101
62
SuzukiS.SargentR. G.IllekB.FischerH.Esmaeili-ShandizA.YezziM. J.et al (2016). TALENs Facilitate Single-step Seamless SDF Correction of F508del CFTR in airway epithelial submucosal gland cell-derived CF-iPSCs.Mol. Ther. Nucleic Acids5e273. 10.1038/mtna.2015.43
63
WangZ. G.ZhangL.ZhaoW. J. (2016). Definition and application of precision medicine.Chin. J. Traumatol.19249–250. 10.1016/j.cjtee.2016.04.005
64
XuC.WuK.ZhangJ. G.ShenH.DengH. W. (2016). Low-, high-coverage, and two-stage DNA sequencing in the design of the genetic association study.Genet. Epidemiol.14272–75. 10.1002/gepi.22015
65
XueY.LameijerE. W.YeK.ZhangK.ChangS.WangX.et al (2016). Precision medicine: what challenges are we facing?Genomics Proteomics Bioinformatics14253–261. 10.1016/j.gpb.2016.10.001
66
YuanB. (2016). How do precision medicine and system biology response to human body’s complex adaptability?Chin. J. Integr. Med.22883–888. 10.1007/s11655-016-2605-z
67
ZiętkiewiczE.RutkiewiczE.PogorzelskiA.KlimekB.VoelkelK.WittM. (2014). CFTR mutations spectrum and the efficiency of molecular diagnostics in polish cystic fibrosis patients.PLoS ONE9:e89094. 10.1371/journal.pone.0089094
Summary
Keywords
CFTR, genotype, gene-therapy, lung disease, phenotype, variability
Citation
Marson FAL, Bertuzzo CS and Ribeiro JD (2017) Personalized or Precision Medicine? The Example of Cystic Fibrosis. Front. Pharmacol. 8:390. doi: 10.3389/fphar.2017.00390
Received
03 April 2017
Accepted
02 June 2017
Published
20 June 2017
Volume
8 - 2017
Edited by
Wanqing Liu, Purdue University, United States
Reviewed by
Jing Xie, Emory University, United States; Juergen Reichardt, Yachay Tech University, Ecuador
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Copyright
© 2017 Marson, Bertuzzo and Ribeiro.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Fernando A. L. Marson, fernandolimamarson@hotmail.com
This article was submitted to Pharmacogenetics and Pharmacogenomics, a section of the journal Frontiers in Pharmacology
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