The Ontario newborn screening program at the Children’s Hospital of Eastern Ontario (CHEO), Ottawa, has fulfilled the Ministry of Health and Long-Term Care’s mandate to screen all babies born in Ontario for 28 different, rare genetic disorders.
CHEO reached the milestone April 9, when it began offering genetic testing for cystic fibrosis (CF) using the xTAG™ cystic fibrosis kit developed by Luminex Corp, Austin, Tex.
“The Luminex CF kit provides a robust, user-friendly system to test a large number of samples for a broad panel of clinically relevant CF mutations, allowing us to screen more than a hundred samples every week from newborn babies that have been identified as being at high risk for having CF,” said Pranesh Chakraborty, MD, a pediatrician and lab director for the program. “This, in turn, means that babies who have CF can be diagnosed earlier and their health can be improved by starting treatment at an earlier age.”
Newborn screening in Ontario had remained virtually unchanged from 1978 through 2005, but in November 2005, the Ministry decided to cast a wider net. The infants’ blood samples are are screened for metabolic and genetic disorders, such as sickle cell anemia, congenital adrenal hyperplasia, and cystic fibrosis.
CF is the most common autosomal-recessive disorder in the Caucasian population. It is estimated that one in every 3,600 children born in Ontario is affected with the disease. Early detection and treatment has been shown to reduce therapeutic needs, lower rates of complications, and increase life expectancy. Late diagnosis of the disease is frequently associated with chronic lung infections and compromised growth.
CF screening begins by assessing an infant’s blood IRT (immunoreactive trypsinogen) level from a dried blood-spot sample obtained from a heel prick. A high IRT suggests possible CF and requires further testing. Those samples showing an IRT level above the 96th percentile are tested with the CF kit, which simultaneously screens for the 39 most common CF gene mutations and four variants.
The program performed 826 tests using the Luminex test within the first 6 weeks of genetic testing for CF. From that group, 47 babies were identified as being at high risk for having CF and referred to a treatment center for a follow-up assessment with a specialist.
“Through its newborn-screening mandate, the government of Ontario has recognized the significant health benefits that early detection affords people who are diagnosed with CF,” says Jeremy Bridge-Cook, VP of Luminex Molecular Diagnostics. “We salute the newborn screening program at CHEO for having accomplished its ambitious goal and are honored that Luminex’s cystic fibrosis kit has aided in its endeavor.”
The company’s CF kit also screens for the 23 CFTR gene mutations and 4 variants (polymorphisms) that were recommended by the American College of Medical Genetics and American College of Obstetricians and Gynecologists in 2004, plus 16 of the world’s most common and North American-prevalent mutations.
With validated performance criteria, the kit is a highly accurate and reproducible (>99.9%) test that furnishes mutation coverage for carrier screening in adults and as an aid to diagnosis in newborns. The FDA cleared the multiplexing assay for diagnostic use in May 2005.
Luminex develops, manufactures, and markets proprietary biological testing technologies with applications in the diagnostic and life sciences industries.
