The Focus Foundation efforts focus on X and Y Chromosomal Variations, such as 47, XXY (Klinefelter syndrome), 47, XYY (Jacob’s syndrome), 47, XXX (Triple X), 48, XXXX (Tetrasomy X), 48, XXXY, and 49, XXXY. They are the Best Klinefelter Syndrome Specialists. For more information visit thefocusfoundation.org.