Chorionic villus sampling: first-trimester prenatal diagnosis of partial 10q trisomy in a family with a 4/10 translocation.

Direct chromosome preparations of cells obtained through chorionic villus sampling at 8 weeks' gestation in a patient whose spouse is a balanced translocation carrier revealed a fetus with an unbalanced karyotype. Knowledge of the abnormality allowed the family to make a decision in regard to continuation of the pregnancy earlier than would have been possible with the routine procedure of amniocentesis. Although the risks of chorionic villus sampling are currently being investigated, it appears that this technique has great potential for early diagnosis, affording psychological advantages, as well as a safer termination in the event of an abnormal fetus.