New Study Shows Screening Based on Self-Reported Ethnicity Fails to Identify Significant Percentage of Pregnancies Affected by Serious Genetic Conditions

SALT LAKE CITY, Aug. 10, 2020 (GLOBE NEWSWIRE) -- Myriad Genetics, Inc. (NASDAQ: MYGN), a leader in molecular diagnostics and precision medicine, announced today a new study published in the peer-reviewed journal Genetics in Medicine demonstrates the limitations of ethnicity-based medical guidelines in identifying couples at risk for a pregnancy affected by serious genetic conditions. The analysis of 93,419 individuals found substantial discordance between self-reported ethnicity and actual genetic ancestry.

In the new study, researchers at Myriad assessed the ability of a 96-disease screen to identify carriers in an ethnically diverse population, comparing the results to those obtainable via ethnicity-based screening. They also compared the genetic ancestry of the population to self-reported ethnicity. Results showed that only 23 percent of carriers would have been identified through ethnicity-based screening protocols supported by societal guidelines. Further, for seven of the 16 diseases included in the guidelines, most carriers were not from the populations that the American College of Obstetricians and Gynecologists (ACOG) and the American College of Medical Genetics and Genomics (ACMG) have indicated were at higher risk of the respective genetic disorders.

“Due to changing demographics and increased intergroup marriage, the risk of passing along genetic diseases is no longer concentrated in specific ethnicities,” said lead researcher Dale Muzzey, Ph.D., vice president of bioinformatics at Myriad Genetics. “At the same time, a large proportion of patients cannot accurately identify the ethnicities of their ancestors. Combined, these factors point to the need for more efficient and equitable carrier screening for a comprehensive list of genetic disorders.”

In the past decade, the evolution of carrier screening methodology has enabled scalable screening of many serious single-gene diseases simultaneously, termed expanded carrier screening (ECS). Although panethnic ECS, as offered to all patients without regard to ethnicity, has established analytical validity, clinical validity, clinical utility, and cost-effectiveness, both ACOG and ACMG currently stop short of recommending that ECS be preferentially offered. Instead, screening based on self-reported ethnicity continues to be endorsed as a standard.