Mayo Clinic Improves Diagnoses of Rare Diseases with Genomic Testing

Rare Daily Staff

A Mayo Clinic study found increased use of genomic testing such as multi-gene panels, exome sequencing, and genome sequencing in the past decade, provided greater opportunity to better diagnose and treat patients with rare diseases.

In the four-year study, published in the Journal of Translational Medicine, researchers evaluated 1,152 patients with rare diseases and performed genomic testing on 855 patients and also evaluated and tested patients’ family members. As a result, 42.7 percent of the solved or likely solved patients had changes in their medical approaches based on the genomic testing results.

“Genomic testing has proven to be an accurate, scalable, and affordable tool for healthcare providers to diagnose rare diseases for patients with complex medical histories,” said Konstantinos Lazaridis, director of the Mayo Clinic Center for Individualized Medicine. “However, challenges remain for practitioners who lack the time, expertise, appropriate tools, or experience to interpret genomic findings correctly.”

Lazaridis said that determining the cause of rare diseases is arduous and time-consuming and requires specific skills, including training in sequence variant interpretation. There is also a need for communication and education of the health care provider, patient, and their family.

In 2018, the Mayo Clinic Center for Individualized Medicine created the Program for Rare and Undiagnosed Diseases to integrate genomics-based care into practice, including targeted genomic testing, research, and education for patients with rare diseases and their families.

The program has an integrated team and process to support physicians leading the use of genomic testing in patient care. The team of clinicians, genetic counselors, and research scientists has been integral in evaluating and validating genetic variants derived from multi-gene panel testing. That has led to increased access to testing, better diagnosis, improved patient care, new knowledge, and academic studies.

The authors note that 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 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.

In 2020, Mayo Clinic developed its Genetic Testing and Counseling Unit to improve access to and increase the efficiency of genomic testing. The unit includes genetic counseling for patients and genomic test ordering via sub-specialty clinicians. It provides a streamlined approach to enhance access to focused genetic testing and counseling for identified conditions, reduce referral time, and give just-in-time education to clinicians with limited access to genomic testing and no formal genetics training.

The researchers note that the model bridges a critical genomic testing and counseling access gap, maintaining continuity of care while providing referrals for those patients who would most benefit from further evaluation with trained medical geneticists.

They suggested that a hybrid telehealth service could increase the number of patients diagnosed, reduce the time it takes to get that diagnosis, and expand testing for rare diseases where it has been underused.

“It helps patients understand testing options’ expectations and limitations, the potential effect on clinical management and the consequences to family members,” says Filippo Pinto e Vairo, the first author of the study.

Photo: Konstantinos Lazaridis, director of the Mayo Clinic Center for Individualized Medicine