Many people say that it seems like certain rheumatic and autoimmune diseases run in families, but doctors simply didn’t have the data to back up that assumption — until now.
A recent study examined whether nine pediatric-onset autoimmune ailments, including the juvenile form of rheumatoid arthritis, might be inherited.
The study, which was published in a recent issue of Nature Communications, was made up of genetic data collected by 20 doctors and hospital systems both in the United States and overseas.
The scientists looked at genes and related factors to see if different autoimmune diseases in a single family might have a common genetic trigger.
This research may help researchers and medical professionals more accurately and precisely predict the onset of autoimmune illness in children.
"The results from this study enable us to better understand the genetic component of these diseases and how they are genetically related to each other, thereby explaining why different autoimmune disorders often run in the same family,” said Dr. Hakon Hakonarson, Ph.D., an assistant professor of pediatrics and director of the Center for Applied Genomics at The Children's Hospital of Philadelphia, who lead the study.
Juvenile Arthritis Scores High in Study
Of the nine conditions studied, type 1 diabetes and juvenile idiopathic arthritis appeared to be the most likely to be inherited.
This coincides with what doctors have long expected — that there is a genetic component at play for people with autoimmune diseases.
The study also examined the overlap of autoimmune ailments. Some conditions do tend to “pair off” with other similar diseases.
Although children with juvenile arthritis can have any number of coinciding ailments, the most common pairing in the study was juvenile idiopathic arthritis and common variable immunodeficiency syndrome.
Heritability also seemed more common in children with autoimmune diseases than their adult counterparts.
Aside from juvenile arthritis, the scientists studied type 1 diabetes, celiac disease, common variable immunodeficiency, systemic lupus erythematosus, Crohn's disease, ulcerative colitis, psoriasis, and ankylosing spondylitis.
The researchers on the study compared these conditions to pediatric-onset epilepsy, which is not believed to have an autoimmune component. The researchers examined genome data from the autoimmune and epilepsy patients, and then 5,000 patients in the study were compared with 35,000 healthy control patients.
These findings could help scientists to develop individualized medical treatments for patients, based on their genes. The potential for targeted drug therapy could be life-altering for autoimmune patients of all ages.
"We envision that we may be able to develop new therapies that may help significant subsets of patients across multiple autoimmune diseases who share the same genetic variants that result in perturbations of normal biological functions and autoimmunity," said Hakonarson. "This is the foundation for precision medicine approaches.”
A Patient Perspective
Juvenile arthritis is a painful, chronic autoimmune disease of rheumatic nature.
While many people do not associate forms of arthritis with pediatric medicine, juvenile arthritis is the sixth most common childhood disease.
Rebecca Whitehead of North Carolina is hopeful it can be better treated.
Whitehead lives with rheumatoid arthritis and ankylosing spondylitis. Her daughter, Bailey, was diagnosed with juvenile idiopathic arthritis at age 4. Now, at age 10, she is thought to have another related autoimmune condition called juvenile dermatomyositis.
Whitehead says that her mother and aunts also lived with undiagnosed rheumatoid arthritis for many years.
“I always knew it in my gut that these diseases were inherited somewhere along the line, somehow,” she said. “But our doctors always said that it wasn’t proven to be genetic. I carry guilt that my genes could have caused my daughter’s illnesses, but I hope that studies like this will help find a cure based on those genes — or at least a way to prevent these conditions for my future grandkids someday. I pray every day.”
What Do Officials Say?
The Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH) have yet to confirm that all cases of juvenile arthritis are inherited.
“Most cases of juvenile idiopathic arthritis are sporadic, which means they occur in people with no history of the disorder in their family. A small percentage of cases of juvenile idiopathic arthritis have been reported to run in families, although the inheritance pattern of the condition is unclear. A sibling of a person with juvenile idiopathic arthritis has an estimated risk of developing the condition that is about 12 times that of the general population.”
New research, like this latest study, could help uncover more answers for future generations of juvenile arthritis patients and parents.