New Myriad Genetics Study Published in Prenatal Diagnosis Shows High Positive Predictive Value for 22q11.2 Microdeletion Syndrome Using Prequel Prenatal Screen

SALT LAKE CITY, April 16, 2024 (GLOBE NEWSWIRE) -- Myriad Genetics, Inc., (NASDAQ: MYGN), a leader in genetic testing and precision medicine, today announced that Prenatal Diagnosis has published a study¹ demonstrating exceptional positive predictive value (PPV) for 22q11.2 microdeletion screening using Myriad’s prenatal cell-free DNA (pcfDNA) screen, Prequel, which incorporates fetal fraction amplification.

Prior studies from other commercial pcfDNA laboratories have reported a broad range of PPV for the 22q11.2 microdeletion, with several well below 100%.^2-6 The proprietary AMPLIFY technology in Prequel increases the relative amount of fetal-derived cfDNA more than two-fold on average and was previously shown to increase analytical performance of 22q11.2 microdeletion screening.⁷ The current study shows the clinical performance achieved by Prequel with AMPLIFY: among 22 patients who screened positive for 22q11.2 microdeletion and had diagnostic testing results available, all 22 were confirmed as positive (100%; 95% confidence interval: 84.6%-100%).

“With AMPLIFY, we've overcome a major technical limitation of 22q11.2 microdeletion screening and observed a PPV that we believe is among the highest published for a clinically available prenatal cfDNA screening assay,” said Dale Muzzey, PhD, Chief Scientific Officer, Myriad Genetics. “This is now the second publication—one from Myriad and another from a separate laboratory⁵—showing exemplary PPV for whole-genome-sequencing-based pcfDNA screening. Notably, the PPV levels are considerably higher than what has been reported for SNP-based pcfDNA screening, where approximately half of reported positives were false positives.”⁶

“These results are among the most promising our field has seen for early 22q11.2DS detection. This study enables greater confidence for providers when they receive positive screening results for 22q11.2 microdeletion. Patients can be more effectively guided toward further testing and management options that are best suited for their situation,” said James Goldberg, MD, FACOG, FACMG.

22q11.2 deletion syndrome (22q11.2DS), often called DiGeorge syndrome, is caused by deletions on chromosome 22 (22q11.2 microdeletions). 22q11.2DS can result in a wide range of health problems, including congenital heart defects and immune-system disorders. Detecting 22q11.2DS during pregnancy allows for better informed pregnancy management, including monitoring that can improve outcomes for newborns. The American College of Medical Genetics and Genomics recently recommended that 22q11.2DS screening be offered to all pregnant patients.