Chapter 17 - Congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)»Chromosomal abnormalities, not elsewhere classified (Q90-Q99)»Klinefelter syndrome, unspecified (Q98.4)
Q98.4
Klinefelter syndrome, unspecified
Related indications (MeSH) (1)
A form of male HYPOGONADISM, characterized by the presence of an extra X CHROMOSOME, small TESTES, seminiferous tubule dysgenesis, elevated levels of GONADOTROPINS, low serum TESTOSTERONE, underdeveloped secondary sex characteristics, and male infertility (INFERTILITY, MALE). Patients tend to have long legs and a slim, tall stature. GYNECOMASTIA is present in many of the patients. The classic form has the karyotype 47,XXY. Several karyotype variants include 48,XXYY; 48,XXXY; 49,XXXXY, and mosaic patterns ( 46,XY/47,XXY; 47,XXY/48,XXXY, etc.).