GENETIC
IMPLICATION OF ENDOGAMY
NEWS: Endogamy
— a major cause for health disparity in India, says CSIR-CCMB study
WHAT’S
IN THE NEWS?
A recent study led by CSIR-Centre for Cellular and Molecular Biology (CCMB)
has focused on understanding the genetic consequences of endogamy in India. The
study highlights the genetic implications of this practice, especially its
contribution to inbreeding and the emergence of genetic disorders within
specific populations.
About
Endogamy:
- Definition of
Endogamy
- Endogamy
is the practice of marrying within a specific community, group, or social
class, rather than marrying outside one’s immediate social circle or
ethnic group.
- This
practice is common in many parts of the world, including India, and has
been prevalent in various cultures, including caste-based communities,
where marriage tends to occur within the same caste or group.
- Impact of Endogamy
on Genetic Diversity
- Inbreeding: Continuous endogamy leads to higher degrees of
inbreeding, where individuals marry close relatives or members of the
same community over generations.
- Genetic
Pool: The
limited genetic pool resulting from inbreeding increases the likelihood
of inheriting genetic disorders, as harmful recessive genes that may be
rare in a larger population become more prominent within a smaller gene
pool.
- Consequences of
Endogamy
- Over
time, endogamous practices reduce genetic diversity within communities,
making them more susceptible to certain inherited diseases.
- It
also reduces the population’s ability to adapt to environmental changes,
as genetic variation is essential for evolutionary progress and
resistance to diseases.
Key
Findings of the Study:
- Study Details
- The
research involved analyzing 281 high-coverage whole-exome sequences from
four anthropologically distinct populations across India. Whole-exome
sequencing is a technique that focuses on the protein-coding regions of
the genome, which are believed to have the most impact on health and
disease.
- The
study aimed to assess the extent of inbreeding within these populations
and the emergence of genetic variants associated with specific diseases.
- Genetic Variations
Linked to Population-Specific Diseases
- The
study found that genetic variations linked to certain diseases are more
prevalent in specific communities due to the high levels of endogamy.
This suggests a relationship between inbreeding and the emergence of
genetic disorders that may be rare in the general population but more
common in isolated communities.
- Incidence of
Ankylosing Spondylitis in the Reddy Community
- One
significant finding of the study was the higher incidence of ankylosing
spondylitis, a type of arthritis that primarily affects the spine,
within the Reddy community in Andhra Pradesh.
- This
condition is genetically linked, and its increased prevalence in
endogamous populations indicates the role of inbreeding in exacerbating
the genetic predisposition to this disease.
- Pharmacogenomic
Findings
- Pharmacogenomics: The study also examined pharmacogenomic markers,
which are genetic variations that affect how individuals metabolize and
respond to medications.
- It
was found that there are significant differences in how different Indian
populations metabolize common drugs. These variations can influence the
effectiveness of treatments and the risk of adverse drug reactions.
- Drugs Affected by
Genetic Variations
- Tacrolimus: This is an immunosuppressive drug used to prevent
organ rejection in transplant patients. The study found variations in how
different populations metabolize tacrolimus, which could impact its
efficacy and safety.
- Warfarin: This anticoagulant drug, used to prevent blood
clots, was also found to have different metabolic rates in various
populations. The study suggests that genetic differences could affect how
individuals respond to warfarin, leading to either excessive bleeding or
insufficient anticoagulation.
Pharmacogenomic
Markers:
- Definition of
Pharmacogenomic Markers
- Pharmacogenomic
markers are specific genetic traits that influence how individuals
respond to drugs. These markers can indicate whether a drug will be
effective, what dosage is appropriate, and the risk of adverse side
effects.
- These
markers may include differences in the DNA or RNA sequences that encode
for drug-metabolizing enzymes, drug transporters, or the drug's target
molecules within the body.
- Types of
Pharmacogenomic Markers
- Genetic
Variants:
These are differences in the DNA sequence that affect how enzymes or
transporters involved in drug metabolism work. For example, some genetic
variants can lead to slower or faster metabolism of certain drugs.
- Gene
Expression Levels:
Variations in how much of a certain gene is expressed can also affect
drug response. High or low expression levels of genes can influence how
effectively the body processes and responds to medications.
- Applications of
Pharmacogenomic Markers
- Personalized
Medicine:
Pharmacogenomic markers are increasingly used in personalized medicine,
which tailors drug treatments based on an individual’s genetic makeup.
This ensures that the patient receives the most effective medication with
the least risk of side effects.
- Drug
Development:
Identifying genetic markers that predict drug responses can help
pharmaceutical companies develop more effective drugs. These markers can
guide the creation of drugs that are more suited to the genetic profiles
of specific populations.
Conclusion:
The study by CSIR-CCMB underscores the genetic consequences of endogamy in
India, including its role in increasing inbreeding and genetic disorders. It
also highlights the need for personalized medicine, where understanding genetic
differences in drug metabolism can lead to more effective and safer treatments
for individuals from different populations.
Source: https://www.thehindu.com/news/national/telangana/endogamy-a-major-cause-for-health-disparity-in-india-says-csir-ccmb-study/article69290229.ece