News in brief - June 6, 2005

DNA-based CF diagnostic test available - African-Americans more likely to have a stroke at a younger age

DNA-based CF diagnostic test available

The Food and Drug Administration last month approved the first DNA-based blood test to aid in cystic fibrosis diagnosis. The Tag-It Cystic Fibrosis Kit can detect variations in the cystic fibrosis transmembrane conductance regulator gene that cause many cases of this disease.

"This test represents a significant advance in the application of genetic technology and paves the way for similar genetic diagnostic tests to be developed in the future," said Daniel Schultz, MD, director of the FDA's Center for Devices and Radiological Health.

Because the test does not detect all genetic variations responsible for the disease, the agency recommends that results only be used for diagnosis in conjunction with a physician's interpretation of the patient's clinical condition, ethnicity and family history.

The test can also be used to detect carriers of these genetic variations.

African-Americans more likely to have a stroke at a younger age

Because of a higher rate of strokes earlier in life, African-Americans lose twice the number of years of life expectancy to this disease as do Caucasians. Stroke death rates are also significantly higher overall among blacks, but much of the disparity is due to differences in educational levels and other risk factors, according to papers published in the May 20 Morbidity and Mortality Weekly Report.

Researchers at the Centers for Disease Control and Prevention analyzed data collected from death certificates and the Behavioral Risk Factor Surveillance System. For African-Americans younger than 45, the risk of death from stroke was 2.5 times that of whites. For those ages 45 to 54, the risk was 3.5 times higher. When researchers took into account risk factors that increase the likelihood of stroke, much of the racial disparity disappeared. The authors called for more public health programs to address these stroke risks in order to reduce these disparities.

"It is critical that we properly address the risk factors for stroke, such as diabetes, high blood pressure, smoking, and overweight and obesity," said George A. Mensah, MD, acting director of the CDC's National Center for Chronic Disease Prevention and Health Promotion.