Nav: Home

Children's genes affect their mothers' risk of rheumatoid arthritis

October 19, 2014

BETHESDA, MD - A child's genetic makeup may contribute to his or her mother's risk of rheumatoid arthritis, possibly explaining why women are at higher risk of developing the disease than men. This research will be presented Tuesday, October 21, at the American Society of Human Genetics (ASHG) 2014 Annual Meeting in San Diego.

Rheumatoid arthritis, a painful inflammatory condition that primarily affects the joints, has been tied to a variety of genetic and environmental factors, including lifestyle factors and previous infections. Women are three times more likely to develop rheumatoid arthritis than men, with peak rates among women in their 40s and 50s. Certain versions of the immune system gene HLA-DRB1, known collectively as the shared epitope alleles, are associated with the condition. HLA genes are best known for their involvement in the immune system's response to infection and in transplant medicine for differentiating between one's own cells and those that are foreign.

The female predilection of rheumatoid arthritis strongly suggests that factors involved in pregnancy are involved, said Giovanna Cruz, MS, graduate student at the University of California, Berkeley, and first author on the new study.

"During pregnancy, you'll find a small number of fetal cells circulating around the mother's body, and it seems that in some women, they persist as long as several decades. Women with rheumatoid arthritis are more likely to have this persistence of fetal cells, known as fetal microchimerism, than women without the condition, suggesting that it is a potential risk factor for the development of rheumatoid arthritis," Ms. Cruz said. "Why it happens, we don't know, but we suspect HLA genes and their activity may be involved," she explained.

The researchers analyzed the genes of women with and without the shared epitope or other forms of HLA genes associated with risk of rheumatoid arthritis, and their children. They found that having children with these high-risk alleles - inherited from the children's father - increased the women's risk of rheumatoid arthritis, even after accounting for differences among the mothers' genes. These results showed that beyond a woman's own genetic risk of rheumatoid arthritis, there is additional risk conferred by carrying and bearing children with certain high-risk alleles.

"We don't yet understand how the shared epitope and other HLA alleles influence rheumatoid arthritis risk, but one possibility is that interactions between the proteins these genes encode may stimulate the autoimmune symptoms of the disease," Ms. Cruz said. In other words, a woman's immune system may detect proteins produced by the fetus and mistakenly tag lingering fetal cells as a threat, causing an immune reaction and symptoms of rheumatoid arthritis.

In addition to explaining why women are at increased risk of rheumatoid arthritis, the findings may lead to new ways of assessing a woman's risk of disease depending on whether her children or partner carries high-risk versions of genes, an area of research that Ms. Cruz and her colleagues are planning to explore. Other future research includes genetically analyzing multiple generations of rheumatoid arthritis cases, including mothers of people with the disease, and further exploring the role of HLA-encoded proteins and microchimerism.
-end-
Press Availability: Ms. Cruz; Lindsey Criswell, MD, MPD, DSC, of the University of California, San Francisco; and Lisa Barcellos, PhD, MPH, of the University of California, Berkeley, will be available to discuss this research with interested media on Sunday, October 19, 2014, from 3:45-4:30 p.m., in the ASHG 2014 Press Office (Room 22).

Reference: Cruz G et al. (2014 Oct 21).

Abstract: Increased risk of rheumatoid arthritis (RA) among shared epitope-negative (SE-) mothers with shared epitope-positive (SE+) children: Results from the Mother-Child Immunogenetic Study in Autoimmunity (MCIS). Presented at American Society of Human Genetics 2014 Annual Meeting. San Diego, Calif.

American Society of Human Genetics

Related Immune System Articles:

Too much salt weakens the immune system
A high-salt diet is not only bad for one's blood pressure, but also for the immune system.
Parkinson's and the immune system
Mutations in the Parkin gene are a common cause of hereditary forms of Parkinson's disease.
How an immune system regulator shifts the balance of immune cells
Researchers have provided new insight on the role of cyclic AMP (cAMP) in regulating the immune response.
Immune system upgrade
Theoretically, our immune system could detect and kill cancer cells.
Using the immune system as a defence against cancer
Research published today in the British Journal of Cancer has found that a naturally occurring molecule and a component of the immune system that can successfully target and kill cancer cells, can also encourage immunity against cancer resurgence.
First impressions go a long way in the immune system
An algorithm that predicts the immune response to a pathogen could lead to early diagnosis for such diseases as tuberculosis
Filming how our immune system kill bacteria
To kill bacteria in the blood, our immune system relies on nanomachines that can open deadly holes in their targets.
Putting the break on our immune system's response
Researchers have discovered how a tiny molecule known as miR-132 acts as a 'handbrake' on our immune system -- helping us fight infection.
Decoding the human immune system
For the first time ever, researchers are comprehensively sequencing the human immune system, which is billions of times larger than the human genome.
Masterswitch discovered in body's immune system
Scientists have discovered a critical part of the body's immune system with potentially major implications for the treatment of some of the most devastating diseases affecting humans.
More Immune System News and Immune System Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.