Balanced reciprocal translocations detected at amniocentesis

Area of Science:

• Cytogenetics
• Prenatal Diagnosis
• Reproductive Genetics

Background:

• Balanced reciprocal translocations are chromosomal rearrangements that can be detected during prenatal diagnosis.
• Amniocentesis is a common procedure for prenatal genetic testing.

Purpose of the Study:

• To analyze perinatal outcomes, reasons for detection, and parental choices in cases of balanced reciprocal translocations identified via amniocentesis.
• To provide insights into the genetic counseling challenges associated with these findings.

Main Methods:

• Retrospective analysis of 87 cases diagnosed with reciprocal translocations or complex chromosomal rearrangements (CCRs) via amniocentesis between 1987 and 2010.
• Review of parental ascertainment methods, de novo occurrences, associated fetal anomalies, and pregnancy outcomes.

Main Results:

• Common ascertainment reasons included advanced maternal age and previous affected children.
• Approximately 22.4% of cases were de novo, with some associated with congenital anomalies or requiring termination.
• Concomitant aneuploidy or de novo CCRs were linked to fetal anomalies.

Conclusions:

• Balanced reciprocal translocations can be associated with fetal anomalies, particularly in de novo CCRs or cases with aneuploidy.
• Genetic counseling for de novo simple reciprocal translocations is challenging due to parental decisions for termination.
• Detailed ultrasonography and array comparative genomic hybridization aid in parental counseling for these complex genetic situations.