Background: The Decode Duchenne (DD) industry-sponsored genetic testing program provides testing for individuals with a suspected or confirmed diagnosis of Duchenne or Becker muscular dystrophy (DMD/BMD). DD began with diagnostic testing in 2013 and added carrier testing in 2018. DD is administered by genetic counselors at Parent Project Muscular Dystrophy. Testing was initially performed at Emory/EGL and then transferred to PerkinElmer Genomics in 2017.
Methods: We analyzed DD data including patient demographics, ordering provider (OP), test type and results. We compared data collected during the initial 4.5 years of the program (December 2013-May 2018) with data collected in the most recent 4.5 years (June 2018-November 2022). Both datasets cover 53 months.
Results: A total of 2,439 tests have been performed through DD, including 1,534 diagnostic and 905 carrier tests. Detection of out-of-frame (OOF) vs in-frame (IF) variants has shifted, from 78% OOF for initial years to 69% for recent years. The age at testing has shown a downward trend in recent years, with an average age of 15 years in initial dataset versus 13.9 years in recent dataset. The type of OP has remained consistent, with most tests ordered by specialist physicians. The type of testing has shifted almost entirely to DMD sequencing using NGS, which detects both sequence and copy number variants, versus the two-step testing approach used in initial years. The variant type and the percent amenable to approved therapeutics have remained consistent in both datasets. A decrease in diagnostic tests was observed in recent years.
Conclusions: DD is an extremely valuable program in the DMD/BMD community despite a decrease in testing in recent years (likely due to the pandemic and the availability of other sponsored testing programs). DD has adapted to the needs of the community and now includes carrier testing, neuromuscular panel testing, and RNA sequencing.