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potential for transforming the state of healthcare globally. The underlying principles of inheritance as envisaged by Gregor Johann Mendel remain and the variability occurs due to several genetic and non-genetic factors. The genetic factors could be like gene mutations. Studies indicate that genetic factors could contribute to as much as 95per cent of the variability in treatment response (NCBI ). Traditionally, pharmacogenetics considered drug response as monogenic, following the Mendelian principles. Over time multifactorial genetic influences were looked at in Pharmacogenetics, such as the influence of environment, and this widened the horizon. Pharmacogenetics now also considers variability in gene expression which may arise due to other factors such as drug induced variation, rather than a mutation. With systematic and procedural advances pharmacogenetics evolves into the wider discipline of pharmacogenomics. Pharmacogenomics helps identify the underlying genetic causes of common diseases, which implies that new and more precise drug targets can be identified. This further implies therapies with not just improved drug safety but also better efficacy. Once the right drug targets are determined, patients can be categorized into different genetically defined classes by virtue of race or population sub-groups with a particular gene. These are groups that are likely to have similar reaction to a drug. Lung conditions such as the Interstitial lung diseases (ILD) can benefit significantly with Pharmacogenomics given the observed variability in patient outcomes with current standards of care (PubMed , ResearchGate ). Lung diseaseepidemiology
Lungs are a vital organ for survival, pumping over 20,000 breaths in a day, they keep all the body organs alive by infusing the required amount of oxygen. Studies indicate that upto four million people die prematurely due to chronic respiratory diseases (Annals of
Global Health ). Different lung conditions have varying prevalence across the globe. Prevalence of Interstitial lung diseases (ILD) has been noted to range from 6.3 to 71 per 100,000 people. In North America and Europe, Idiopathic Pulmonary Fibrosis and Sarcoidosis are the most prevalent forms of ILD observed. There is wide variation observed in the prevalence of ILD alone.For instance in countries of Asia like India and Pakistan, Hypersensitivity Pneumonitis has relative higher frequency. In some other countries such as Belgium, Canada and Saudi Arabia, connective tissue disease ILD has relative higher prevalence. This significant variation in prevalence of ILDs is not a reflection of the actual prevalence in the underlying population but also represents the differences in disease classification. Lack of standard ontologies and lack of globally representative data or comparative epidemiological studies on ILD are all opportunity areas for enabling global effort in disease management. How can pharmacogenomics help
ILD constitutes a set of heterogeneous, inherited, lung conditions, which show significant variation in response to therapies. Also referred to as Fibrotic interstitial lung diseases (ILDs), these conditions are associated with high mortality rate, tend to have an unpredictable disease course but also have clinical features that frequently overlap (PubMed ). The disease susceptibility and progression both have genetic association. With the application of pharmacogenomics, the genetic factors that influence the response to treatment, can be understood. Drug metabolism and disease activity are both influenced by different genetic factors. Several genetic associations have been established for conditions like Idiopathic Pulmonary Fibrosis (IPF), one of the Interstitial lung diseases and the most common fibrotic lung disease, with the application of genomic technology. Several studies have indicated the susceptibility to IPF and also mortality to be
associated with certain genes. Studies have also indicated toxicity and severe adverse drug reactions with the current standard lines of treatment in conditions such as IPF – a patient suffering from IPF and treated with Azathioprine developed severe alveolar haemorrhage (European Respiratory Journal ). The potential that Pharmacogenomics holds is not just in avoiding situations of such ADRs but also identifying the right drug and dose for each patient for improved efficacy in conditions such as IPF. IPF is a chronic condition with unknown etiology and high rates of mortality. With the application of the principles of Pharmacogenomics, an individual's molecular data and the 'omics' data (viz genomic, proteomic, epigenomic) can be used for identifying strategies for disease prevention and management. The Pharmacogenomic concepts can be applied to both the sporadic and familial forms of IPF and offers significant hope for better disease outcome through effective and timely predictions and overall disease management. This approach holds significant potential in not just personalizing treatment for IPF patients but also identifying the need for lung transplant. Over time cumulative data from such approaches can help in stratifying patients basis their omics data and planning the right disease management approaches for them (PubMed ). Similarly in COPD, inhaled corticosteroids are commonly prescribed but patient outcomes and even Adverse Drug Reactions tend to vary with the same therapy for patients because of known genetic linkages (PubMed ). Besides other lung conditions, Pharmacogenomics holds great potential in lung cancer treatment as well. Chemotherapy in Lung Cancer is known to substantially improve overall survival as also progression-free survival. However, ADRs and even mortality is known post chemotherapy and patient outcomes show significant variation. Thereby there is need for individual specific dose and
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