Though the true cause of Crohn's disease is unknown, research suggests a genetic component to the disease.
People who have a close relative with Crohn's, such as a parent or a sibling, are much more likely to have Crohn's themselves. The Mayo Clinic states that as many as 1 in 5 people with Crohn's have a close family member with the disease.
Though it can be present in any ethnic or racial group, Crohn's disease is more prevalent in Caucasian populations and Jews with eastern European ancestry, also known as Ashkenazi Jews.
The Hebrew University of Jerusalem explains that over the years, Ashkenazim have generally married within their own ranks, therefore creating a genetic makeup unique to them. This has also led to a greater frequency amongst the Ashkenazim of diseases with causes that are in whole or in part the result of genetic factors.
These include Tay-Sachs, Gaucher disease, Bloom syndrome, Idiopathic torsion dystonia, Familial dysautonomia.
Since Ashkenazim Jews also have a higher risk for Crohn's, the genetic link is being explored as a possible explanation.
Researchers believe that certain human chromosomes may have a role to play in whether or not someone gets Crohn's disease.
Chromosomes are found within cell nuclei and are tightly bound packages of the genetic material that provide instructions for how an organism functions. Humans have 46 pairs of chromosomes in their cells, inherited from their mother and their father.
There can be variations in these chromosomes, and sometimes a variation can cause a problem in the function of a person's body or at least increase the risk of a problem.
The National Institute of Health states that suspicion has fallen on chromosome 5 and chromosome 10 in relation to Crohn's disease. Chromosome 5 is one of the largest human chromosomes and chromosome 10 plays at least some role in governing the body's immune response.
Genetics is not the only area being explored for a cause.
Since the disease tends to be more prevalent among urban populations, environmental factors such as pollution and diet are also being explored. Even the possibility of an as yet undiscovered bacteria or virus is being studied.
“There is increasing evidence that genetics play a relatively large role in the development of Crohn’s Disease,” states Charles T. Richardson, M.D., a gastroenterologist with Baylor University Medical Center in Dallas, Texas.