The XYY syndrome should never be interchanged with the XXY syndrome which is popularly known as the Klinefelter's syndrome. XYY syndrome is a condition when a male patient acquires an extra Y chromosome in addition to the normal one X and one Y chromosomes. It is often argued whether the term 'syndrome' should be used in connection to the XYY condition since the patients' phenotypes are normal and they do not have knowledge of their karyotype.
47 XYY syndrome is not an inherited condition. This is just the result of an accidental event during sperm cell formation. The 'accident' happens either during metaphase I or metaphase II.
This condition cannot be corrected but to prevent the occurrence of this syndrome on the patient's posterity, it is best that genetic testing must be done.