Absence of sperm sex chromosome aneuploidies in an X0/XYY man.

OBJECTIVE

To determine appropriate genetic counseling of patients with a mosaic karyotype who wished to undergo assisted reproduction technology.

DESIGN

Case report.

SETTING

A tertiary center for assisted reproduction technology.

PATIENT(S): A male with a mosaic karyotype X0/XYY.

INTERVENTION(S): Analysis of ejaculated spermatozoa by using fluorescence in situ hybridisation with probes directed against chromosomes X, Y, and 18.

MAIN OUTCOME MEASURE(S): Degree of sex chromosome aneuploidies in spermatozoa.

RESULT(S): Levels of sex chromosome aneuploidies in spermatozoa were normal. On the basis of these findings, the couple proceeded to assisted reproduction technology without preimplantation genetic diagnosis and conceived a healthy male baby.

CONCLUSION(S): Sex chromosome mosaicism in men does not necessarily lead to high levels of abnormal spermatozoa. Sex chromosome aneuploidies may be eliminated in the testes through the selective degeneration of abnormal spermatogenic cells.