[Fertility in Klinefelter syndrome]

Abstract

In Klinefelter syndrome with non-mosaic 47,XXY caryotype, a biological paternity can be obtained by TEsticular Sperm Extraction and Intra-Cytoplasmic sperm injection (TESE-ICSI). TESE is positive in about 50 % of the cases in published series of non-mosaic 47,XXY Klinefelter syndrome. Age is the main prognosis factor for TESE. Among patients seeking children, the percentage of positive TESE is higher in younger men. Sperm cells are extracted from focal spermatogenesis. They differenciate from spermatogonia which have corrected their chromosome complement (46,XY). The risk of aneuploidy is similar in Klinefelter syndrome and in non-obstructive azoospermia with normal caryotype. Among more than 100 born children reported in the literature, all have a normal caryotype. Only one foetus, within a triple pregnancy, had a 47,XXY caryotype. Whether the percentage of positive TESE is better for adolescent than for adult Klinefelter patients should be addressed by performing a TESE in adolescent (from 15 years old) similarly to adult Klinefelter patients. TESE will be followed by cryopreservation of extracted sperms. They will be used latter for ICSI when the patient will seek children. This early TESE can be performed before the beginning of the androgenic treatment, avoiding the potential deleterious feedback effect of exogenous testosterone on the gonadotropin secretion and on the focal spermatogenesis. Any androgenic treatment should be interrupted at least six months before the TESE to avoid the feedback lowering effect on gonadotropin secretion.