XCAT-TS is a non-karyotype genetic test for identification of Classic and Mosaic forms of Turner Syndrome. The test’s quantitative genotyping, using pyrosequencing technology, allows for accurate identification of Turner Syndrome with clinically meaningful sensitivity and specificity in both Classic and Mosaic TS patients. Our molecular genetic approach uses markers spanning the X-chromosome’s p and q arms to detect loss of  heterozygosity, allowing this highly specific and scalable assay, to accurately determine the number of X-chromosomes from buccal swab DNA. The addition of a Y chromosome marker to our testing panel allows us to detect Y-chromosome fragments, whose presence predisposes to increased cancer risk in TS patients. The validation data for this test was published in the Journal of Clinical Endocrinology and Metabolism in Feb 2011. For a PDF version of this paper, please click on the following link: J Clin Endocrine Metab. February 2011, 96(2)