Implication of Genetic Testing and Pregnancy Outcome in a Woman with Unbalanced Translocation t(1;6)

Abstract

Case series Patients:— Final Diagnosis: 1p36 deletion • duplication 1p36.31 (0.22 Mb) and deletion 6q27 (1.2 Mb) • duplication 1p36.33p36.31 (5.4Mb) and deletion 6q27 (1.2 Mb) • unbalanced translocation t(1;6) Symptoms: Multiple adverse pregnancy outcome Medication: — Clinical Procedure: — Specialty: Genetics • Obstetrics and Gynecology Objective: Rare disease Background: Parental chromosomal structural abnormalities can lead to diverse chromosomal imbalances at meiotic segregation during gametogenesis and subsequent early pregnancy loss or birth of a child with a chromosomal abnormality. The incidence of unbalanced translocations is 1 per 1000 newborns versus 3 per 1000 newborns for balanced rearrangements. Here, we present the case of a mother with an unbalanced chromosomal trans-location and her offspring. Case Reports: Our patient had a 1p36.31 duplication of 0.22 Mb and 6qter deletion of 1.2 Mb. She had 5 pregnancies with different outcomes. Her first child died 24 h after birth due to a congenital heart defect. Her second pregnancy resulted in the birth of a girl who was postnatally diagnosed with 1p36 deletion syndrome. The third and fourth pregnancies ended spontaneously in the first trimester. For her last pregnancy, the patient underwent a diagnostic amniocentesis at the 16 th week of gestation. A large 5.4-Mb pathogenic duplication of 1p36.33 was detected in the fetus and the woman decided to terminate the pregnancy. Conclusions: In this case report, we detail the different pregnancy outcomes induced by the mother’s unbalanced chromosomal translocation and review the prenatal diagnostic genetic testing. Our report clearly demonstrates the complementary nature of chromosomal microarrays and conventional karyotyping .