Context:
The role of X chromosome in auto-immune diseases
Autoimmune Diseases:
- It occurs when immune system is overactive, causing it to attack and damages body’s own tissues
- During this condition, body system cannot distinguish between invaders and healthy cells.
- Common types – Multiple Sclerosis, Type 1 diabetes etc.
- Causes by – Environmental factors, genetics, hormonal imbalance and lifestyle habits.
A study by University of Oxford stated that about 10% of the population they had studied who had autoimmune diseases of which 13% were women and 7% were men.
Role of X chromosome
- X chromosome inactivation
- The molecular coating of the X chromosome which ensures that one set of X chromosomes in females remains active and functional in all the cells of the body while the other is inactive.
- Estrogen has a strong effect on the immune system
- When there is an imbalance or inflammation of the estrogen hormone, the risk of autoimmune disease increases among women
Key terms:
- Chromosome – Thread like structures made of protein and a single molecule of DNA that serve to carry the genomic information from cell to cell
- Chromosomal difference –
- Male and female embryos carry 22 identical pairs of chromosomes.
- The 23rd pair is different – Females carry two Xs, while males carry an X and a Y, which leads to the development of male sex organs.
- Most of the genes in the second X-chromosome in females are inactive and non-functional but few of the genes in this second X-chromosome are active.
Source: The Hindu
Previous Year Question
With reference to the recent developments in science, which one of the following statements is not correct?
[UPSC Civil Services Exam – 2019 Prelims]
(a) Functional chromosomes can be created by joining segments of DNA taken from cells of different species.
(b) Pieces of artificial functional DNA can be created in laboratories.
(c) A piece of DNA taken out from an animal cell can be made to replicate outside a living cell in a laboratory.
(d) Cells taken out from plants and animals can be made to undergo cell division in laboratory petri dishes
Answer: (a)
