While previously Klinefelter syndrome (KS) patients with pure 47, XXY karyotype were invariably considered sterile, the finding of focal spermatogenesis and the recovery of spermatozoa for ICSI has changed their fertility outcome. Unfortunately, no cogent clinical predictive factors for successful testicular sperm extraction are available to select KS patients for this procedure.
Since germ cell depletion starts with the onset of puberty, early testicular tissue sampling might offer a higher chance to retrieve sperm cells than testicular tissue sampling at adult age.
We hypothesize that in KS adolescents spermaturia might be present in the early stages of puberty and that SSCs could be found at biopsy.
We also want to study the possibility and necessity of testicular tissue cryopreservation in prepubertal KS boys. Because germ cell transplantation or tissue grafting might not be feasible at adult age due to the ongoing destruction of the tubular and interstitial architecture that occurs in adulthood, we consider that cryopreservation might be worthwhile as in vitro maturation techniques may evolve and become feasible in the future.