Role of X Chromosome in Autoimmune Diseases

Context: 

A study in 2023 by University of Oxford showed that 13% of autoimmune diseases occur in women and 7% in men. 

Key Findings of the Report

• High susceptibility of women: Autoimmune disease affects women more than men. 

• • A team of scientists suggests that the presence of a molecular coating on about half of the X chromosomes in women is the reason behind this phenomenon. 
• Regional Differences: Research identifies socioeconomic, seasonal, and regional differences in autoimmune disorders.
  • Factors beyond genetics, like smoking, obesity, and stress contribute to disease development.
• Risk Factor: Individuals with one autoimmune disease are at increased risk of developing another.

About Autoimmune Disease

• Autoimmune diseases occur when the immune system mistakenly harms the body’s healthy cells. 
  • For Example: Rheumatoid arthritis, Crohn’s disease, and various thyroid disorders.

Why Is Autoimmune Disease More Common in Women?

• Genetics: Women have two X chromosomes, whereas men have only one. 
  • This difference increases the chance of mutations coming from the X chromosome, which can lead to autoimmune diseases.
• XIST: The X chromosome has long RNA strands called XIST, which trigger inflammatory responses from the immune system. 
  • XIST is active only in cells with two X chromosomes therefore women are at a higher risk of autoimmune diseases and immune attacks.
  • Howard Chang’s observation of male mice showed that many proteins drawn to XIST also cause the production of autoantibodies, which are a kind of antibody that reacts with the body’s own substances.
• Hormonal Changes: Autoimmune diseases often appear during big hormonal changes in a woman’s life, like puberty, pregnancy, and menopause. 
  • These changes in hormones greatly affect the immune system. 
    • For example, skin conditions like psoriasis can be influenced by hormones. Since women undergo more hormonal changes than men, they are more likely to have autoimmune diseases.

News Source: TheHindu

DOWNLOAD PDF