Prenatal diagnosis of double aneuploidy, 48, XXY, +21 (Down-Klinefelter syndrome)

The occurrence of double aneuploidy in the same individual is a relatively rare phenomenon and the incidence varies according to the literature. We report an exceptional case of double aneuploidy with an additional chromosome 21 characteristic of Down syndrome and an additional XXY complement characteristic of Klinefelter syndrome. In this woman the first-trimester screening test, nuchal translucency was 3.8 mm. Then early genetic diagnosis by chorionic villi sampling was done. The result was double aneuploidy (48, XXY, +21) and the pregnancy resulted in a spontaneous abortion at 13th weeks of gestation. We report a case of double aneuploidy with a review of the literature of other cases of Down-Klinefelter double aneuploidy to determine the prevalence, phenotype, sonographic findings, and pathogenesis.