Test checks early for growth condition

YALE (US) — Being short is not usually cause for concern, but is often the only sign of a genetic condition that short-circuits normal growth and can lead to cardiac and renal problems.

Prevalent in girls, Turner syndrome is not commonly detected until age 10 or older delaying the start of growth hormone therapy which can help in achieving normal or near-normal adult stature.

Researchers have developed an inexpensive, accurate, and practical diagnostic test for Turner syndrome that can be done in a doctor’s office.

Details are published online and in an upcoming print issue of the Journal of Clinical Endocrinology & Metabolism.

“We’ve developed a practical test that can be used to test large numbers of girls, and is much quicker and less expensive than the current method called cytogenetic analysis by karyotype,” says Scott Rivkees, professor of pediatrics at Yale University and the study’s lead author.

“The new test would also provide the benefit of early detection of other health conditions associated with TS, such as potential renal and cardiac problems.”

The syndrome, that occurs when an X-chromosome is completely or partially deleted, affects one in 1,500 to 2,000 females. Untreated girls with TS achieve an average height of 4 feet, 8 inches.

The test was developed based on a quantitative method of genotyping to detect X-chromosome abnormalities and was validated from DNA samples from more than 500 individuals. Of 90 clinically confirmed TS individuals tested, the assay correctly identified 87.

“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,” Rivkees says. “If broadly used in the clinical setting at young ages, this test can prevent the delayed recognition of TS.”

More news from Yale University: http://opa.yale.edu/