RESUMO
BACKGROUND: Most of the literature suggests that unbalanced chromosomal translocations may lead to poor obstetrical outcomes. We present a case of an unbalanced translocation resulting in trisomy 1q and partial monosomy 20p identified on chorionic villous sampling (CVS). METHOD: Case report with expert-derived clinical management and guidance. RESULTS: After the abnormal CVS result, a subsequent amniocentesis revealed a normal 46,XX fetal karyotype. Detailed second trimester ultrasound of the fetus revealed no gross structural abnormalities. The CVS karyotype results were attributed to confined placental mosaicism (CPM) of the unbalanced translocation. The infant is 18 months old and has normal phenotype and karyotype. CONCLUSION: We recommend that if CPM with an unbalanced translocation is diagnosed on CVS, parental karyotype and an amniocentesis should be offered in conjunction with genetic counseling. In rare instances, such as this one, an unbalanced translocation may have a favorable outcome.