True about klinefelter syndrome :

Klinefelter syndrome is seen in 1:500 males. The patient with this rare disorder externally resembles a male in general body conformity, the penis is small or normal in size, the testes are small, but as a rule are normally placed. Sterility is common, gynaecomastia is frequently present the voice may be high pitched, and the appearance may be eunuchoid. The patient is often mentally defective or delinquent. Most of these individuals are sex chromatin positive like females because of the extra X chromosome. Genetic analysis reveals their karyotype to be 47 XXY. Testicular biopsy usually reveals hyaline degeneration of the seminiferous tubules and overgrowth of Leydig cells as a result of which sterility is so often the presenting symptom. Sole-to-pubic length is more than normal. The person should be bred as male and should not be told about chromosomal abnormality. Testosterone may help. The breasts may need surgical excision. Shaw's Textbook of Gynaecology 16th edition page no 147