Balanced Translocation and Miscarriage

picture: ghr.nlm.nih.gov




I had never heard of balanced translocation until I received an email from a woman whose husband has the condition. I looked it up and thought it might be of interest to some of my blog readers. This article explains what the condition is and how it may affect conception and pregnancy:

www.parentingweekly.com

From the article:

To better understand the difference between balanced and unbalanced translocation, imagine a part of chromosome 21 has attached itself to chromosome 14. In a balanced translocation, the person has a smaller than normal chromosome 21 with a piece broken off, a normal second chromosome 21, a chromosome 14 with the broken piece of 21 attached, and a normal chromosome 14. The person appears completely normal and suffers no related health problems. If this person wants to have children, however, there are several possibilities that could affect the outcome of the pregnancy.

Both normal chromosomes - The normal chromosomes 21 and 14 may be passed on, resulting in a normal baby.
Broken 21, affected 14 - The broken chromosome 21 and affected chromosome 14 (with the broken piece from chromosome 21 attached) may be passed on, resulting in a baby with the same balanced translocation as the parent, but no related.
Normal 21, affected 14 - The normal chromosome 21 and affected chromosome 14 may be passed on, giving the child extra DNA from chromosome 21, resulting in unbalanced translocation and Down's Syndrome.

The cause of translocation is not well understood, though it has been linked to radiation exposure. There are a wide range of medical problems that may result from the condition, including leukemia, breast cancer, schizophrenia, muscular dystrophy and Down's Syndrome. The related health problems suffered by a person with translocation depend on which part of which chromosome is moved to where.