This document describes the use of newborn screening laboratory tests for detecting risk for cystic fibrosis from newborn dried blood spots (DBS) and addresses both the primary screening tests and the reflex tests performed on DBS.
CLSI Publishes New Guideline: Newborn Screening for Cystic Fibrosis (I/LA35-A)
Wayne, Pennsylvania, USA—November 2011—The Clinical and Laboratory Standards Institute (CLSI) recently published Newborn Screening for Cystic Fibrosis—Approved Guideline (I/LA35-A). This document describes the use of newborn screening laboratory tests for detecting risk for cystic fibrosis from newborn dried blood spots (DBS) and addresses both the primary screening tests and the reflex tests performed on DBS.
“The main benefit of this document is that it provides comprehensive guidelines for early diagnosis of cystic fibrosis through newborn screening,” says Philip Farrell, MD, PhD, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA, and Chairholder of the committee that developed the document. “Improvements in newborn screening processes can assure that early diagnosis of cystic fibrosis is expedited for almost all patients before symptoms develop and patients can benefit from early therapy.”
Cystic fibrosis, a relatively common genetic disorder, is due to mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Early diagnosis through newborn screening is now practiced throughout the United States, Australasia, and many western European countries, and Canadian provinces.
“Due to the rapid development of newborn screening for cystic fibrosis, there have been inconsistences and uncertainties on how to screen newborns for cystic fibrosis,” Dr. Farrell explains. “The international document development committee that created this guideline has cleared up those inconsistences by covering all aspects of newborn screening for cystic fibrosis including strategies, protocols, recommendations, as well as laboratory and clinical follow-up. This guideline serves newborn screening laboratories and cystic fibrosis centers around the world by providing detailed descriptions of best practices.”
The document focuses on the use of immunoreactive trypsinogen (IRT) assays and the detection of specific CFTR mutations with the IRT/deoxyribonucleic acid (DNA) screening strategy. Variations in the IRT/DNA method are also summarized with explanations of their advantages and disadvantages. Special attention is given to CFTR mutations in geographically and ethnically diverse populations. A core panel of CFTR mutations is recommended, with guidance included on its potential expansion.
I/LA35 provides a global resource for newborn screening programs to evaluate current procedures and practices for all aspects of the cystic fibrosis newborn screening system, including follow-up components of sweat chloride testing and genetic counseling. The intended target audience includes newborn screening laboratory and program personnel, regulatory agencies, cystic fibrosis center personnel, neonatologists, primary care providers, organizations responsible for networks of cystic fibrosis centers, and a variety of public health policy makers.
This guideline was developed with international consensus and was written with collaboration from the Centers for Disease Control and Prevention and the U.S. Cystic Fibrosis Foundation (CFF), and included members from different newborn screening-related organizations and centers as well as public health laboratories. It has been endorsed by the CFF. A full list of contributors can be found on sample pages on the CLSI website at www.clsi.org.
CLSI is a volunteer-driven, membership-supported, nonprofit organization dedicated to developing standards and guidelines for the health care and medical testing community through a consensus process that balances the perspectives of industry, government, and the health care professions. For additional information, visit the CLSI website at www.clsi.org or call 610.688.0100.
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