Researchers at Yale University in the US have developed an accurate diagnostic test for Turner syndrome, a genetic defect that obstructs normal growth and leads to cardiac and renal problems. Turner syndrome occurs when an X chromosome is completely or partially deleted, and is not commonly detected until age 10. The test, which is based on a quantitative method of genotyping to detect X-chromosome abnormalities, was developed and validated from DNA samples of more than 500 individuals. In a study involving 90 patients with clinically confirmed Turner syndrome, the new test correctly identified 87. Scott Rivkees, lead author of the study, said that because of the small amount of DNA needed for the test, sample DNA can be extracted from cheek swabs, or from newborn screening blood spots that are routinely collected. “If broadly used in the clinical setting at young ages, this test can prevent the delayed recognition of Turner syndrome,” Rivkees added.