New Paper Describes Accurate, Scalable Method for Detecting Fragile X Syndrome in Newborns

Fragile X syndrome is an X-linked disorder that leads to developmental problems, including learning disabilities and cognitive impairment

RESEARCH TRIANGLE PARK, N.C. — A new paper by researchers at RTI International, a nonprofit research institute, and Asuragen, Inc., an Austin, Texas-based molecular diagnostics company, describes a practical and accurate solution for high-volume newborn screening for fragile X syndrome.

The solution, called the “FMR1 PCR Assay System,” is designed to detect fragile X syndrome from dried blood spots. Analysis of 963 de-identified newborn dried blood spot samples using the FMR1 PCR Assay System identified 957 normal and six premutation specimens, consistent with previously published prevalence estimates of fragile X syndrome.

“Previous methods designed to screen newborns for fragile X syndrome have been impractical to implement for routine, high-volume use in state laboratories,” said Don Bailey, PhD, an RTI distinguished fellow and director of RTI’s Center for Newborn Screening, Ethics, and Disability Studies. “That is not the case with this method. It can test for fragile X accurately and at a large scale — a truly exciting advancement for the field of newborn screening.”

The FMR1 PCR Assay System can detect fragile X syndrome in both males and females and can also identify a newborn who is a carrier of fragile X syndrome despite not having the condition. Knowing that an infant is a carrier means that a parent is also a carrier and at risk for having other children with fragile X syndrome.  The precision of the assay system allows screening programs to determine which cut-off scores are most appropriate for screening.

“Asuragen’s breakthrough products for analyzing the fragile X gene provide sensitive, reliable and scalable results for clinical research and applications that are described in more than 100 peer-reviewed publications.  This important new study with RTI expands these applications to newborn screening by integrating custom AmplideX® PCR reagents, controls, and automated software into a complete system,” said Gary Latham, PhD, senior vice president of Research & Development at Asuragen. 

Fragile X syndrome, also referred to as FXS, is an X-linked disorder that leads to developmental problems, including learning disabilities and cognitive impairment. An estimated one in 4,000 males and one in 8,000 females are born with fragile X syndrome each year. While the condition does not have a cure, testing at birth allows for early intervention therapies in the event of a positive test.

Investigators at RTI’s Center for Newborn Screening, Ethics and Disability Studies are now using this assay to offer voluntary fragile X screening to parents in North Carolina, as part of a research project known as Early Check.

The paper was published in The Journal of Molecular Diagnostics and was supported by the National Center for Advancing Translational Sciences, part of the National Institutes of Health, and The John Merck Fund.

To learn more about RTI’s Center for Newborn Screening, Ethics, and Disability Studies, visit: www.rti.org/impact/newborn-screening-ethics-and-disability-studies.

To learn about Early Check, RTI’s partnership with the North Carolina State Laboratory of Public Health to allow newborns in North Carolina to be tested for fragile X syndrome and spinal muscular atrophy at no cost, visit: www.earlycheck.org.