Risk Assessment and Prenatal Diagnosis in a Recent Pregnancy in a Family with a Child with Down Syndrome due to t (21q;21q)

We here present a family with a boy with 21q;21qtype translocation of Down syndrome. He was six years old. His clinical presentation included the classical findings of Down syndrome. We found 46,XY, -21, + t(21q;21q) chromosomal consitution in all metaphases obtained from peripheral blood cells of the child (Figure 1). Then we examined his parents. Both spouses were 32 years old. They were healthy people with no consanguinity between them. Following cytogenetic studies, it was determined that they were not carriers for 21q;21q translocation. Their chromosomal structures were normal. The boy’s mother was admitted counseling for her most recent pregnancy; from her history we learned that the had gravidity 3, parity 1, and D&C 1. The second pregnancy was terminated by D&C at the 7 week of gestational age at the parents’ wishes two years ago. This pregnancy was at the 15 week of gestational age. We performed amniocentesis during the 16 week of gestational age; fetal karyotype revealed 46,XX. This pregnancy resulted in the birth of a healthy female child. After delivery, cytogenetic tests were conducted on chord blood to confirm the amniotic results. The results of the tests were identical.