Human genome editing: significance and associated challenges – Explained, pointwise

Introduction  

Experts from around the world recently gathered in London for the Third International Summit on Human Genome Editing. The summit discussed the latest advancements in technology and emphasized the importance of responsible use. While human genome editing offers potential solutions to many challenges, it also raises ethical, legal, and regulatory concerns. Therefore, it is crucial to understand and address these challenges to ensure ethical and responsible use of the technology.  

What is Human genome editing?  

Genome editing is a method for making specific changes to the DNA of a cell or organism. It can be used to add, remove or alter DNA in the genome. Human genome editing technologies can be used on somatic cells (non-heritable), germline cells (not for reproduction) and germline cells (for reproduction).  

For example, scientists can use CRISPR-Cas9, a type of genome editing tool, to cut and modify specific parts of the DNA in a cell. This could potentially be used to treat genetic diseases by correcting the underlying genetic mutations responsible for the disease.  

How Human genome editing is done?

What is the need for Human genome editing? 

Increasing Genetic disorders: India is considered as the “Pandora’s Box of genetic disorders. India has a high prevalence of rare recessive genetic diseases due to its population’s heterogeneity and inbreeding rates. Human genome editing could potentially address this issue by correcting or eliminating disease-causing mutations in affected individuals or preventing the transmission of these mutations to future generations.  

Rising incidence of viral disease: According to the World Health Organization, an estimated 2.1 million people in India were living with HIV in 2019, with a prevalence rate of 0.2. 

Cancer as a growing health concern:  According to The Report of National Cancer Registry Programme, 2020 India’s cancer burden could increase from 1.39 million during this year to 1.57 million in 2025. Human gene editing can address this burden.

Rising issues of side effects of treatment: Genome editing can be used to create personalized medicine based on an individual’s unique genetic makeup. This could lead to more effective and efficient treatments with fewer side effects.  

Increasing food allergies: According to a study published in the Indian Journal of Pediatrics, the prevalence of food allergies in Indian children is estimated to be around 6-8%. Human gene editing can also be used to create allergy-free foods.  

What are the advantages of Human genome editing?  

Potential cures for genetic diseases: Genome editing could potentially offer a cure for genetic diseases that currently have no effective treatments. For example, using genome editing to correct the genetic mutation responsible for cystic fibrosis could cure the disease.  

Can treat cancer diseases: Human gene editing can improve the accuracy and efficiency of cancer modeling, which is crucial for developing cancer therapies. For instance, The Cancer Genome Atlas (TCGA), a cancer genomics program in the US, has already mapped genomic changes in 33 cancer types in order to improve cancer treatment.

Can treat viral diseases: Human genome editing has the potential to cure viral diseases by modifying the patient’s own immune cells to better target and destroy the virus. One approach is to use CRISPR-Cas9 to edit the DNA of T cells, a type of immune cell, to make them resistant to HIV infection. Another approach is to use CRISPR-Cas9 to remove the hepatitis B virus from infected liver cells.

Increase understanding of the human genome: Studying the effects of editing specific genes could help researchers better understand the role of those genes in human biology and disease.  

Advancements in scientific research: Genome editing can be used to create animal models of human diseases, allowing scientists to better understand the mechanisms of these diseases and develop new treatments.   

Enhanced biosecurity: Genome editing can be used to develop disease-resistant animals, preventing the spread of zoonotic diseases.  

Improving agricultural productivity: Genome editing could be used to create crops that are more resistant to pests, require less water or are more nutritious, leading to increased agricultural productivity and food security. It’s worth noting that while there are potential advantages to genome editing, there are also significant ethical and safety concerns that must be carefully considered before any widespread use of the technology. 

What are the challenges associated with Human genome editing?  

Ethical concerns: The use of gene editing raises ethical questions such as whether it is appropriate to genetically engineer embryos, or to modify traits that are not related to the disease. For instance, editing genes to enhance intelligence or physical appearance could lead to unintended consequences and exacerbate social inequalities.  

Concerns over “designer babies”: There are concerns that genome editing could be used to create “designer babies” for social rather than medical reasons. This raises ethical concerns and could lead to the creation of a genetically-engineered elite. For example, editing the genes of an embryo to increase its intelligence could create a societal divide between those who have access to technology and those who do not.  

Off-target effects: Gene editing could unintentionally modify genes other than the targeted one, causing unpredictable consequences. For example, a study published in 2017 reported that CRISPR-Cas9 gene editing resulted in unexpected mutations in mice.  

Safety concerns: Gene editing could lead to unintended consequences, such as off-target effects or immune reactions, that could pose a risk to the health of the individual undergoing the procedure. For example, editing the wrong gene could cause a person to develop cancer.  

Germline editing: Until now, all therapeutic interventions in humans using genome editing have been performed in somatic cells (i.e. only the patient gets affected, no chance of inheriting the altered genes by the patient’s offspring).

But, editing the germline can lead to unpredictable changes that can be passed on to future generations. This raises ethical and safety concerns. For example, editing the genes of a human embryo can result in unintended genetic changes that can be passed down to offspring.  

Note: Germline gene editing involves altering the specific genes of an egg, sperm cell, or early embryo (i.e., up to five days after fertilization) in a laboratory dish. Germline gene editing removes, disrupts, alters, or corrects faulty elements of DNA within a gene in sex cells.  

Lack of long-term data: The long-term effects of gene editing are not yet fully understood, and there are concerns that modifications made to an individual’s DNA could have unintended consequences that only become apparent years or even decades later. For example, there may be unforeseen consequences of using CRISPR to eliminate a particular disease-causing gene that is not fully understood.  

Regulatory challenges: At present, there is no regulating body to keep a check on the practices and applications of Human genome editing technology. It may therefore lead to reduced transparency, low quality and may also increase the unnecessary delay in the treatment of patients.

Further creating a strong regulatory oversight can be difficult to achieve given the rapidly evolving nature of the technology and the varying regulatory approaches taken by different countries.

For example, the US FDA currently regulates gene-edited animals as drugs, while in Europe they are considered to be genetically modified organisms (GMOs) and are subject to different regulations.  

Ecological impacts: Gene drives can be used to propagate a set of genes with negative traits throughout a population, which can lead to severe ecological consequences. For example, introducing gene-edited mosquitoes that are resistant to malaria could lead to the elimination of the mosquito population, which could disrupt the ecosystem.  

Uncontrolled clinical trials: There are currently no standard norms for clinical trials to check the efficacy of genome editing treatment. This can lead to uncontrolled clinical trials, which can result in patients receiving ineffective or potentially harmful treatments.  

What should be done before permitting widespread applications of human genome editing?  

Continued research: Further research is needed to fully understand the potential benefits and risks of human genome editing. This includes long-term studies on the safety and efficacy of different gene editing techniques, as well as research on the ethical, social, and legal implications of the technology.  

Responsible use: It is important that human genome editing is used responsibly and ethically, with appropriate regulation and oversight. This includes ensuring that the technology is used only for medical purposes and that it does not exacerbate existing inequalities.  

Collaboration and transparency: Collaboration between scientists, policymakers, and the public is important to ensure that human genome editing is used responsibly and transparently. This includes open communication about the potential benefits and risks of the technology, as well as consultation with the broader public on key ethical and policy issues.  

Development of ethical guidelines: The development of clear ethical guidelines is important to ensure that human genome editing is used responsibly and ethically. This includes guidelines on issues such as the use of gene editing for non-medical purposes, the editing of germline cells, and the informed consent of individuals undergoing the procedure.  

Investment in infrastructure: Investment in infrastructure is needed to support the development and deployment of gene editing technologies. This includes investment in research facilities, regulatory agencies, and public health systems, as well as the development of international standards and protocols for the use of gene editing.  

Educate the public: The public should be educated about the potential benefits and risks of human genome editing, as well as the ethical and social implications of the technology. This can help to ensure that public opinion and policy decisions are informed by accurate and up-to date information.  

Sources: Times of India, NYTimes, BBC, NCDIR, and WEF

Syllabus: GS 3: Science and Technology – Science and Technology developments and their applications and effects in everyday life.