Genetic testing for diabetes: creating the guidelines together

Towards best practice guidelines for genetic testing of monogenic subtypes of diabetes

RESEARCH QUESTIONS  

  1. What is the current practice of genetic testing for MODY?
  2. What should be the best practice?
  3. Can we reach a consensus and develop best practice guidelines regarding genetic testing for monogenetic subtypes of diabetes mellitus? 

Duration: March 2011 - present. 

SUMMARY

Many patients with Maturity-Onset Diabetes of the Young (MODY) are currently undiagnosed or misdiagnosed with type 1 or 2 diabetes. Genetic testing for maturity-onset diabetes of the young (MODY) may be relevant for treatment and prognosis in patients with usually early-onset, non-ketotic, insulin-sensitive diabetes. A genetic diagnosis also enables monitoring of asymptomatic family members. The project aimed to describe the current state of genetic testing for MODY in the Netherlands, explore experiences with genetic testing among patients and health care professionals, and to probe future needs. By providing a platform for experts in the field and discussing their opinions on the current and best practice of genetic testing of for MODY, including their perceived barriers and disadvantages of genetic testing, the researchers aimed to identify next steps in the implementation of consensus guidelines. 

From a laboratory database study it can be concluded that the number of individuals genetically tested for MODY so far in the Netherlands is low compared to previously predicted numbers of patients. In total, 1319 mutation scans for HNF1A, GCK and HNF4A were performed in the Netherlands in 2001-2010. The test-positive rate was ~22%. Cascade testing for a known mutation in family members occurred 296 times, and has not increased over time at the same rate as mutation scanning. In total 502 individuals were identified with a pathogenic MODY mutation. 

Interviews showed that professionals vary in their valuation of genetic testing for MODY; some are not convinced of its (long-term) clinical benefits for patients and family members. Patients as well as (pre)symptomatic family members however were very positive about genetic testing for MODY. Patients as well as professionals perceived a lack of knowledge and awareness amongst professionals and lack of consensus about the division of responsibilities in the care for MODY patients. International experts agreed that genetic testing for MODY should continue; however, more evidence on clinical utility was considered needed. Costs of testing were mentioned as barriers in (international) current practice on MODY testing. Taken together, efforts should be undertaken towards better provision of information about MODY and systematic study of the clinical utility of genetic testing.

More information about this project.