Science & Technology

Context: Human Pangenome Reference Consortium has released a pangenome reference map built using genomes from 47 anonymous individuals (19 men and 28 women), mainly from Africa but also from the Caribbean, Americas, East Asia, and Europe.

What is a genome?

• The genome is the blueprint of life, a collection of all the genes and the regions between the genes contained in our 23 pairs of chromosomes.
• Each chromosome is a contiguous stretch of DNA string, i.e., the human genome consists of 23 different strings, each composed of millions of individual building blocks called nucleotides or bases [adenine (A), cytosine (C), guanine (G), and thymine (T)]. These bases or building blocks (A, T, G and C) are arranged and repeated millions of times in different combinations to make all of our 23 chromosomes.
• Genome sequencing is the method used to determine the precise order of the four bases and how they are arranged in chromosomes. Sequencing individual genomes helps us understand human diversity at the genetic level and how prone we are to certain diseases. 

What is a reference genome?

• Human reference map or reference genome, represents a single, representative genome sequence for a given species or individual. The reference map is typically derived from the genome of an individual that is chosen as a representative of the species or a reference panel of individuals from the same population. 
• When genomes are newly sequenced, they are compared to a reference genome, i.e., it serves as a standard or reference against which other genomes can be compared and aligned. This helps us to understand the regions of differences between the newly sequenced genome and the reference genome.
• One of this century’s scientific breakthroughs was the making of the first reference genome in 2001. It helped scientists discover thousands of genes linked to various diseases; better understand diseases like cancer at the genetic level; and design novel diagnostic tests.
  • The reference genome of 2001 was 92% complete and contained many gaps and errors. Additionally, it was not representative of all human beings as it was built using mostly the genome of a single individual of mixed African and European ancestry.
  • Since then, the reference genome map has been refined and improved to have complete end-to-end sequences of all 23 human chromosomes and is still continuously evolving to fill the gaps.

What is a pangenome? 

• The pangenome refers to the entire set of genes present in a species, including both the core genome (genes present in all individuals) and the accessory genome (genes present in only some individuals or strains).
• A pangenome map typically involves the identification and annotation of genes and their genomic locations within a species. It provides insights into the genetic diversity and variability within a species, as well as the presence of specific genes or gene variants in different individuals or populations.
• By comparing the genomes, researchers can identify shared genes and gene clusters as well as unique genes present in specific individuals. 

Importance of pangenome map:

• Humans are more than 99% similar in their DNA, there is still about a 0.4% difference between any two individuals. This may be a small percentage, but considering that the human genome consists of 3.2 billion individual nucleotides, the difference between any two individuals is a whopping 12.8 million nucleotides.
• A complete and error-free human pangenome map will help us understand those differences and explain human diversity better. 
• It will also help us understand genetic variants in some populations, which result in underlying health conditions. E.g., The pangenome reference map has added nearly 119 million new letters to the existing genome map and has already aided the discovery of 150 new genes linked to autism.

Limitations: 

• The genomes from many populations are still not a part of it. E.g., In the current version of the pangenome map, genomes from people from the Indian sub-continent, indigenous groups in Asia and Oceania, and West Asian regions are not represented.     

To read more about ‘Genome Sequencing and the Genome India Project’, kindly click on the link given below: https://compass.rauias.com/current-affairs/genome-sequencing-and-the-genome-india-project/   

Context: As per a latest study, even low levels of Arsenic consumption may impact cognitive function in children, adolescents, and young adults.

Those exposed to Arsenic had reduced grey matter (brain tissue that is vital to cognitive functions) and weaker connections within key regions of the brain that enable concentration, switching between tasks, and temporary storage of information.

Arsenic contamination of water:

• Arsenic is a natural component of the earth’s crust and is widely distributed throughout the environment in the air, water and land. Highly toxic in its inorganic form, it is introduced into soil and groundwater during weathering of rocks and minerals followed by subsequent leaching and runoff. 
• People are also exposed to elevated levels of inorganic Arsenic through:
  • Drinking or using contaminated water in food preparation and irrigation of food crops
  • Industrial processes (Arsenic is used industrially as an alloying agent, and in the processing of glass, pigments, textiles, paper, metal adhesives, wood preservatives and ammunition)
  • Smoking tobacco (tobacco plants can take up Arsenic naturally present in the soil).

Impacts:

• Long-term exposure can lead to mortality due to chronic Arsenic poisoning, multiple cancers (skin lesions and skin cancer), lung disease, heart attacks, kidney failure and diseases of the skin (colour changes, and hard patches on palms and soles). 
• Negative impacts of Arsenic exposure on cognitive development, intelligence and memory.
• Adverse pregnancy outcomes, infant mortality and impacts on child health.

Management of Arsenic contamination:

• A common strategy employed is to encourage piped water access rather than groundwater extraction, adopting rainwater harvesting/ watershed management practices and installing Arsenic removal plants. 

Context: Recently, the Central Drugs Standard Control Organisation (CDSCO) put out a list of over 50 medicines that were either found to be spurious or ‘not of standard quality’, raising a furore.

What is CDSCO

• India takes pride in its pharmaceutical industry, being the largest global producer of generic medicines that benefit the global poor.
• However, the industry has faced challenges, including struggles to achieve scale and defamatory claims about the ineffectiveness and harm caused by Indian drugs. 
• Quality concerns persist, with numerous drugs failing to meet standards, leading to substandard drugs in routine use and adverse events. 
• Global regulators have raised issues with compliance, potentially damaging India's reputation. Recommendations include amending regulations, centralizing the drug regulatory system, enhancing transparency, and focusing on producing quality generics and innovative drugs.

About Central Drugs Standard Control Organisation (CDSCO)

• It functions as India's national regulatory body overseeing cosmetics, pharmaceuticals, and medical devices. 
• The CDSCO is organized with the Drug Controller General of India (DCGI) overseeing pharmaceuticals and medical devices. 
• It is assigned duties under Drugs and Cosmetics Act, 1940.
• The DCGI is situated within the Ministry of Health and Family Welfare and receives guidance from the Drug Technical Advisory Board (DTAB) and the Drug Consultative Committee (DCC). 
• The CDSCO operates through zonal offices that conduct inspections prior to licensing, post-licensing inspections, post-market surveillance, and, if necessary, initiates drug recalls. 

Context: Moving a step closer to developing India’s first vaccine against dengue, drug-makers Serum Institute of India and Panacea Biotec have submitted their responses to the call by the Indian Council of Medical Research (ICMR) for an Expression of Interest for collaborative Phase 3 clinical trials for indigenous manufacturers.

Major Highlights:

• The Phase 3 trial is being done for evaluation of efficacy, along with safety and immunogenicity of tetravalent dengue vaccine candidate developed by Indian manufacturers. Trials could start close to August 2023 for the adult vaccine.
  • Serum Institute of India’s vaccine initiated one/two studies in the paediatric population and the plan for Panacea’s vaccine is to conduct Phase 3 randomised, double-blind, placebo-controlled trial in 10,335 healthy adults (aged 18-80) in 20 sites (ICMR-funded).
• The desirable characteristics of a dengue vaccine include:
  • Acceptable short- and long-term safety profile (no antibody-dependent enhancement), inducing protection against all four serotypes of dengue, reducing the risk of severe diseases and deaths. 
  • Inducing a sustained immune response and effectiveness irrespective of the earlier serostatus and age of the individual.

Dengue:

• Dengue fever is a viral illness caused by the dengue virus, which is transmitted to humans through the bite of infected Aedes mosquitoes, primarily Aedes aegypti. Dengue cannot spread directly from person to person.
• Dengue is commonly found in tropical and subtropical regions around the world, especially in urban and semi-urban areas.
• Symptoms: Dengue fever typically presents with flu-like symptoms, including high fever, severe headache, joint and muscle pain, and rash. In severe cases, dengue can lead to dengue hemorrhagic fever (DHF) which can be life-threatening.
• Treatment: There is no specific antiviral treatment for dengue fever and early detection and access to proper medical care greatly lower fatality rates of severe dengue. Prevention and control of dengue depend on vector control. 

Dengue causes significant morbidity and mortality across the globe and in India, 2 to 2.5 lakh cases are reported annually. In 2019, the World Health Organization (WHO) identified dengue to be one of the top 10 global health threats.

Context: The World Health Organisation (WHO), after the recommendation of the organisation’s emergency committee, has announced that Mpox is no longer a global health emergency.

About Monkeypox:

• Mpox (monkeypox) is a viral zoonotic disease caused by the mpox virus, a member of the Orthopoxvirus genus.
• Mpox is characterized by rash or skin lesions that are usually concentrated on the face, palms of the hands, and soles of the feet.
• It is mainly spread to people from animals, primarily rodents and monkeys, and human-to-human transmission can occur through contact with bodily fluids, respiratory droplets, or contaminated objects.
• There is currently no specific treatment for mpox, it may be treated with some antiviral drugs used to treat smallpox. Also, monkeypox is self-limiting, which means it can get better without treatment.