We present a prenatal case with a 45,X,dic(Y;15) (q11.23;p11.1) karyotype and describe the inheritance pattern of the chromosome 15s. Chromosome 15 has an imprinted region and inheritance of both chromosome 15 from one parent results in either Angelman syndrome (AS) (paternal inheritance) or Prader Willi syndrome (PWS) (maternal inheritance). Parental chromosome studies revealed that the father carried the same dicentric (Y;15) translocation. Since familial chromosome rearrangements can result in aberrant chromosomal segregation during meiosis, we wanted to exclude paternal uniparental inheritance of chromosome 15. By using DNA microsatellite markers at several 15q11q13 loci, we determined that the fetus had inherited his normal non-translocated chromosome 15 from his mother.