A Mayo Clinic study published in Journal of Translational Medicine evaluated the use of genomic testing broadly for rare diseases. With the increased use of genomic testing such as multi-gene panels, exome sequencing and genome sequencing in the past decade, there is a greater opportunity to better diagnose and treat patients with rare diseases. According to the National Institutes of Health, as many as 10,000 distinct rare diseases exist and an estimated 25-30 million Americans are affected by one of them.
In the four-year Mayo Clinic study, researchers evaluated 1,152 patients with rare diseases, did genomic testing on 855 patients and also evaluated the tested patients’ family members. The overall rate where they either determined or likely determined the cause of the disease was 17.5% and as high as 66.7%, depending on the phenotype (set of observable characteristics of a person resulting from the interaction of its genotype with the environment).
As a result, 42.7% of the solved or likely solved patients had changes in their medical approaches based on the genomic testing results.
Additional findings from the genomic testing study included:
- There is a need for a multidisciplinary team to care for patients going through the genomic testing process. It is also important to understand the limitations of the different types of genomic testing.
- Genomic results may lead to the use of a targeted medication that can speedily resolve a patient’s symptoms and improve their quality of life.
- Genomic testing for common diseases such as diabetes may help with diagnosis and uncover monogenic causes, which are rare, ranging from 1% to 5% of children and young adults. Confirming the diabetes diagnosis can help improve medication management and outcomes for patients and their family members.
- Including a research component in the clinical practice can help reach a definitive diagnosis, which allows for prescribing disease-specific medications or management.
- Genomic testing can help currently unaffected family members of a patient understand if they have an increased risk of developing an inherited familial disease in the future.
