Klinefelter syndrome is diagnosed by
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.
Karyotyping
USG abdomen
Triple test
Echocardiography
Genetic and genetic disorders