Inflammatory bowel disease (IBD) is a complex genetic disorder.
It is characterized by nonmendelian inheritance, incomplete penetrance, and disease susceptibility but not disease certainty.
Genotype and phenotype associations have been previously described.
However, the interest of IBD patients in genetic testing for themselves or at-risk family members remains unknown.
Dr Vani Konda and colleagues therefore assessed the interest of patients with IBD in genetic testing.
The investigative team also evaluated their willingness to accept the uncertainty inherent in complex genetics.
The team recruited consecutive outpatients with IBD to complete a 57-item self-administered survey.
The survey included a layperson explanation of the limits of IBD genetics.
A 5-point Likert scale was used to determine willingness to undergo genetic testing, diagnosis, prognosis, and treatment.
The investigators used the scale to ascertain the patients' willingness to help their family, and to advance medical knowledge.
|88% would undergo testing for therapeutic decision making|
|Inflammatory Bowel Diseases|
The IBD Questionnaire, a validated measure of the health status attitudes of patients with IBD, was used.
The team used the standard reference gamble paradigm to determine limits of patient interest in testing family members.
Patients were presented with situations for the genetic test with various levels of certainty in 10% decrements starting with 100%.
They indicated the lowest degree of certainty that they would accept to test their family member.
The investigators recruited 114 patients with a mean age of 38 years, of which 48% were women.
Of these, 72% had Crohn's disease.
The team noted that among the patients who answered questions on self-willingness, 77% would undergo testing for diagnostic confirmation.
The investigators found that 81% would undergo testing for prognostic value, 88% for therapeutic decision making, and 85% to advance medical knowledge.
The team observed that 28% of patients had a first-degree relative with IBD.
Those patients with a first-degree relative with IBD were more willing to undergo genetic testing than those without a first-degree relative with IBD.
There was no significant association between patients' health status and their willingness to undergo genetic testing.
The team found that 89% of patients indicated an interest in testing family members if the test provided absolute certainty of future disease.
In addition, the investigators observed that the average lowest level of certainty these patients were willing to accept was 42%.
Dr Konda's team conclude, “Despite the complexity of IBD genetics, most patients with IBD are interested in testing, and willing to accept a variable degree of uncertainty about the results.”
“An important minority of patients does not wish to be tested.”
“Future work should better identify the reasons for these different attitudes.”
“This information should be factored into plans for widespread clinical testing.”