Klinefelter's syndrome true CSP2005:1254-8437 MTHICD9_2006:758.7 disease_ontology kleinfelters syndrome (xxy) DOID:1921 UMLS_CUI:C0022735 XXY trisomy Klinefelter's syndrome is a common sex chromosomal abnormality and the most common cause of male hypogonadism. This syndrome is characterized by cognitive and behavioral dysfunction and hypogonadism. Seizures usually start between 3 months and 3 years of age and are typically well controlled with anti-seizure medication. Variable electroclinical characteristics may be seen from patient to patient, however generalized seizures (absence, tonic-clonic) are common seizure types. This disorder is diagnosed on routine karyotype examination. NCI2004_11_17:C34752 MESH:D007713 GARD:8705 SNOMEDCT_US_2018_03_01:22053006 Hypogonadotropic Hypogonadism ICD10CM:Q98.0 ICD10CM:Q98.4 NCI:C34752 Klinefelter syndrome XXY syndrome ICD9CM:758.7 No OMIM mapping, confirmed by DO. [LS]. chromosomal anomaly