Many patients with unsolved medical mysteries often undergo genetic testing, but the tests do not always provide a conclusive diagnosis. The term "diagnostic odyssey" describes the series of clinical consultations and testing that patients with undiagnosed disorders often receive in search of a genetic diagnosis.

To help these patients, Mayo Clinic researchers embarked on a six-year journey, beginning in 2012, to offer exome sequencing to 1,101 patients with rare and undiagnosed diseases. Exome sequencing is a genomic technique for sequencing all of the protein-coding regions of genes in a genome.

Results of the study, which were recently published in Genetics in Medicine, showed:

• When exome sequencing was integrated with translational research, 24.9% of patients, or 274 of 1,101 patients, received a genetic diagnosis.
• On the basis of exome sequencing alone, 15.8% of patients, or 174 of 1,101 patients, were diagnosed.
• The Mayo Clinic Translational Omics program evaluated and provided a diagnosis to 9% of patients, or 100 of 1,101 patients.

"In this large study of unselected patients on a diagnostic odyssey, we set out to show the impact of integrated translational research on exome sequencing in improving the diagnosis of these patients," says Eric Klee, Ph.D., Mayo Clinic co-principal investigator of the study.

Mayo Clinic launched the Individualized Medicine Clinic in 2012 to provide comprehensive genomic testing for patients with rare and undiagnosed diseases. The clinic offers exome testing and includes the new Translational Omics program. Within this program, a team of clinicians, scientists, laboratorians, ethicists and bioinformaticians provide individualized and integrated translational research to resolve uncertain genetic findings or identify genetic variation elusive to standard testing strategies.

"We found integration of the combined expertise and resources of the Translational Omics Research Team to address these diagnostic challenges significantly improved the outcomes obtained from exome sequencing," says Konstantinos Lazaridis, M.D., the Everett J. and Jane M. Hauck Associate Director of Mayo Clinic's Center for Individualized Medicine in Rochester and principal investigator of the study.

Dr. Lazaridis is also the William O. Lund, Jr. and Natalie C. Lund Program Director for Clinomics.

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This article was originally published on the Center for Individualized Medicine blog.

Tags: Center for Individualized Medicine, clinical research, diagnostic odyssey, Eric Klee, genetic testing, genome, Konstantinos Lazaridis, News, rare disease, republished