Prenatal diagnosis of a de novo Y/22 translocation.

Prenatal chromosomal analysis was performed at 17 weeks' gestation because of the previous birth of a girl with trisomy 13. A seemingly balanced de novo Y/22 translocation was diagnosed. Translocations involving the Y chromosome are rare and no similar translocation, detected pre- or postnatally, could be found in published reports. The counselling problems are discussed. The pregnancy ended at term with the birth of a phenotypically normal boy. After birth, the prenatal diagnosis was confirmed and the H-Y antigen expression was determined.