[Prenatal diagnosis of two pregnancies with risk of chromosomal disorders]

To report the prenatal diagnosis of 2 cases of pregnancy with the risk of chromosomal disorders. In Case 1, the pregnant woman had a daughter with testicular regression syndrome and a segmental duplication of Ypter --> Yp11.2 and a deletion of Yq11.23 --> Yqter. In Case 2, both the pregnant woman and her husband were carriers of chromosomal balanced translocation.

Two samples of amniotic fluid were obtained at the 19th week of gestation for fetal karyotype analysis. For Case 1, FISH with a probe of Xp/Yp subtelomere was performed on the metaphase of the amniotic fluid, genomic DNA of the amniotic fluid extracted and multiplex PCR conducted for AZF regions. Both the pregnant women underwent sonography to confirm the karyotypic diagnosis.

Cytogenetic, FISH and multiplex PCR analysis of the cultured amniotic fluid cells from Case 1 showed a normal male karyotype, and ultrasound scan of the fetus showed normal male external genitalia and normal development. Cytogenetic analysis of the cultured amniotic fluid cells from Case 2 revealed a karyotype of balanced translocation with t(13 ; 14) from the father, and no abnormality of the fetus was found by ultrasound scan.

It is helpful to perform cytogenetical and molecular prenatal diagnosis in combination with ultrasound scan for the fetus with the risk of chromosomal disorders and subsequently for genetic counseling.