Your Mother suffers from an Autoimmune disease while your Father is just rocking his chair, I get it that you now wonder why your mum has to go through this after coming all this years to be a mother to your, a grandmother to your kids, and a husband to your father. It isn't like men do not have autoimmune diseases, but according to research, about 80% of patients diagnosed with autoimmune diseases are women. Let's discuss this for clarity.
Autoimmune disorder occurs when the Immune system begins to see your healthy cells as a threat and begin to attack and kill them. There have been about 80 autoimmune diseases identified and to put this to your understand it means your immune system has attacked different cells, tissues, and organs in your body and we can now bring out over 80 different conditions from this attacks.
Image From Wikimedia
Let's start with Lupus which is an autoimmune disorder that can affect major parts of the body including joints, skin, the kidneys, and other organs of the body. At the same time, it has a 9 : 1 female to male bias. Looking at another autoimmune condition known as Hashimoto's Thyroiditis, is 95% prevalent in females. It s not like autoimmune diseases like to select the orange over the grape, like women over men, it is just predominant with people with 2 or more "X" chromosomes.
When we are born, we have 23 pairs or chromosomes with 22 autosomes or non-sex chromosomes and 1 pair of sex chromosomes which is what gives the XX and XY chromosome. With this, you should know that people with additional X chromosomes such as Klinefelter Syndrome with XXY chromosomes or Trisomy X with three X chromosomes are likely to have autoimmune disease but this is not the same for people with Turner syndrome who have one one X chromosome and they are less likely to develop autoimmune disorders. With these scientist come to an hypothesis that it might be the number of chromosome X dosage that increases the likelihood of an autoimmune disease.
Excessive expression of X-linked genes is often seen in Lupus with people with the XX chromosomes and not XY chromosome. A paper published in 2020 reported that female mice with Lupus-like disease had reduced Xist signals in a subset of immune cells which had too many copies of genes from the X chromosome being expressed. Xist (X Inactive Specific Transcript) is an essential RNA gene which is part of the lncRNA class for X chromosome inactivation. While these genes have been implicated in autoimmune conditions, how it causes them is yet to be known and still being researched by scientist.
*Image from Wikimedia
With this, scientist look for faulty X chromosomes when investigating autoimmune disorders. But while females express Xist in their chromosome due to the number of X they possess, another research gave a different result which now looks like it is changing the course of the study. Another report in 2024 confirms that male mouse could express Xist even when it would normally be found in females. When the researchers induced signs of lupus, the mouse mimicked it and the severity of the disease was more in the male mice with Xist than female.
It is said that females who express Xist have them released into the bloodstream when the cell dies and explodes leading to a cascade autoimmune diseases but studies are till being done. When it comes to identical twins, they can also be identical in autoimmune disease. A study showed that identical twins have a 40% chance of both developing diseases like Lupus if any of them have the disease.
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Environmental trigger can also be a factor, but for now, especially with the 2024 studies, it is great to see that we have heading somewhere when it comes to autoimmune disease, also, it can be easy to quickly diagnose people who have a likelihood of developing autoimmune disease if Xist can be identified early in people even before they begin they are diagnosed with any autoimmune disease thereby helping with treatment.
Reference
https://www.niehs.nih.gov/health/topics/conditions/autoimmune
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7292717/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4303597/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7206452/
https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2015.00022/full
https://www.nature.com/scitable/topicpage/monoallelic-expression-8813275/
https://www.cell.com/cell/fulltext/S0092-8674(24)00002-3
https://www.cell.com/cell/fulltext/S0092-8674(24)00002-3
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7237307/
https://www.ncbi.nlm.nih.gov/mesh
https://www.frontiersin.org/articles/10.3389/fcell.2019.00219/full
https://www.sciencedirect.com/science/article/abs/pii/S0896841111001259
