Objective: To determine aneuploidy frequencies in sperm from a patient with normal phenotype and 46,XY/45,X mosaicism in somatic cells (peripheral lymphocytes).
Design: Case report.
Setting: Infertility clinic and genetics laboratory.
Patient: A 30-year-old male with primary infertility and moderate oligoasthenoteratozoospermia.
Intervention(s): Cytogenetic analysis of somatic cells and determination by fluorescence in situ hybridization of aneuploidy frequencies for the gonosomes (sex chromosomes) and chromosome 18 in sperm from whole and Percoll-separated semen.
Main outcome measure(s): Somatic and gametic aneuploidy were scored.
Result(s): Analysis of lymphocyte metaphase cells showed a mosaic 46,XY (90%)/ 45,X (10%) karyotype. Significantly higher frequencies of gonosomal (semen, 1.92% versus 0.70%; Percoll, 1.12% versus 0.46%), and chromosome 18 (semen, 0.89% versus 0.28%; Percoll, 0.26% versus 0.10%) disomy were detected in the sperm of the patient compared with those observed in spermatozoa from a proved fertile control.
Conclusion(s): Significantly higher frequencies of aneuploid sperm suggest that the patient is at elevated risk of producing offspring with numerical chromosome abnormalities.