Panorama Prenatal Screen to be Highly Accurate in Identifying 22q11.2 Deletion Syndrome
Natera today announced the publication of the first major clinical-experience study, which covers the first six months of experience screening for 22q11.2 microdeletion syndrome using the Panorama non-invasive prenatal test (NIPT). The study by Gross, et al. published in Ultrasound in Obstetrics and Gynecology, which evaluated more than 20,000 patients, reported a positive predictive value of 18% and false positive rate of 0.38%. Reflex sequencing all high-risk samples reduced the false positive rate from 0.38% to 0.12%, and increased the positive predictive value (PPV) to 42.3%. Reflex testing of high risk cases for 22q11.2 deletion syndrome at a higher depth of read will be implemented for Panorama clinical cases later this year.
Microdeletions, which are tiny missing pieces of DNA at the sub-chromosomal level, can have serious health implications. Unlike Down syndrome, for which risk increases with maternal age, microdeletions carry equal risk at all maternal ages. After Down syndrome, 22q11.2 deletion syndrome is the second most common cause of congenital heart disease and of developmental delay. Owing to their much smaller size, microdeletions are much harder to detect than aneuploidy. Natera's targeted, SNP-based methodology overcomes this issue. More than seven times the number of 22q11.2 fetal microdeletion cases were detected in this cohort population than competing NIPT methods for which data is available.
"Early identification and intervention in children with 22q11.2 deletion syndrome can make a significant difference in the health and development of the child," said Susan Gross, MD, lead author on the manuscript. "Prenatal screening can alert caregivers about an affected infant, and allow for delivery and treatment at a specialized facility and neonatal treatments designed to mitigate symptoms. The reported PPV and low false positive rate supports use of Panorama as a first-line screen in the general population."