<prompt> Klinefelter syndrome is diagnosed byKaryotypingUSG abdomenTriple testEchocardiography  <response>: Persons with Klinefelter syndrome are identified with the help of karyotyping. 80 of children with klinefelter syndrome have a male karyotype of X-47,XXY,while the remaining 20 have multiple sex mosaicism or structurally abnormal X chromosome Reference: Nelson TB of pediatrics pg 410 edition 19. 