What are Balanced / Unbalanced Translocations?
A chromosomal translocation occurs when a segment of one chromosome breaks off and attaches to another chromosome.
- Balanced Translocation: The chromosome material is rearranged but no genetic information is lost or gained. People with balanced translocations usually have no health problems themselves but may have fertility issues or an increased risk of miscarriage or having children with chromosomal abnormalities.
- Unbalanced Translocation: Extra or missing genetic material is present due to unequal chromosome rearrangement. This can lead to developmental delays, birth defects, or genetic disorders in the child.
Key Features
- Balanced: Genetic material is intact, but rearranged
- Unbalanced: Loss or gain of genetic material, often causing serious health issues
- Often inherited from a parent with a balanced translocation
- Can cause recurrent pregnancy loss, infertility, or congenital abnormalities
Common Health Implications
- Infertility or reduced fertility
- Increased risk of recurrent miscarriage
- Risk of having children with genetic disorders such as Down syndrome, Edwards syndrome, or other chromosomal imbalances
How to Reduce the Risk
- Karyotype testing to identify translocations in parents with fertility problems or recurrent miscarriages
- Preimplantation Genetic Testing for Structural Rearrangements (PGT-SR) during IVF to select embryos without unbalanced translocations
- Prenatal genetic testing (CVS or amniocentesis) during pregnancy for at-risk couples
- Genetic counseling for couples with a family history of chromosomal rearrangements