The diagnosis of klinefelter syndrome at prepubertal age

Abstract

The low rate of diagnosis of Klinefelter syndrome in prepubertal age is due to hard data to interpret about hormonal, testicular and penile modifications. About the penis length, the diagnosis seems to be suspected when it is less than 3 cm at the birth date and below 4.2 cm between 2 and 10 years. An impaired testis growth could be identified by ultrasound when the mean volume is under 0.25 mL in the first 6 months of life and below 0.36 mL in children younger than 10 years. At mini-puberty, a testosterone maximum peak under 210 ng/dL may be strongly suspect. Human chorionic gonadotropin (hCG) test may be useful but at now not standardized. About sperm recovery by TESE or micro-TESE in Klinefelter patients, a combination of testosterone above 216 ng/dL and luteinizing hormone (LH) below 17.5 U/L, showed a higher retrieval in both children and adults. Extrapolation from histological damage in cryptorchid children, get to hypotesize a severe germ cell impairment if testosterone rising, after a second 1500 UI hCG injection, is below 101.9 ng/dL. In adults, a possible positive predictive testosterone value could be above 1000 ng/dL after hCG test. The retrieval rate seems to be better after the age of 16 and before 19, when could be maximum the development of germ cell line and before a massive fibrosis of the testis.