A case of 48,XXYY syndrome detected prenatally by QF-PCR.

We report on the prenatal diagnosis and genetic analysis of a 48,XXYY fetus. A 28-year-old woman was referred for amniocentesis at 18 weeks' gestation because of advanced paternal age. Quantitative-fluorescence polymerase chain reaction (QF-PCR) with small tandem repeat (STR) markers rapidly detected the sex chromosome polysomy from amniotic fluid cells. This abnormality appeared to arise from successive non-disjunction during paternal meiosis I and meiosis II. Cytogenetic analysis revealed a karyotype of 48,XXYY. This case adds to the evidence that an age-related increase in sex chromosomal aneuploidies occurs in sperm. This case also shows that QF-PCR assays can provide rapid prenatal diagnosis of numerical sex chromosome aneuploidy.