Friday, March 27, 2015
Inherited Disorders and Birth Defects
Balanced translocation (5 and 13)
Me and my boyfriend have been discussing having a baby. I`ve always known he had balance translocation but didn`t know anything about this. However, after researching this recently I have discovered there can be many complications when trying to conceive. His mum has balance translocation, and had 7 miscarriages before having my boyfriend, shorty after she had to have a hysterectomy. His cousin has recently been diagnosed with parkinsons disease, and he is due to be tested for the shakes he gets in his hands. Could this be an affect of the balance translocation of 5 and 13, and what complications may we have conceiving and possible effects may it have on our children? Thankyou for anything you can tell me.
A translocation occurs when two pieces of chromosomes break off and switch places with each other. If all the chromosomal material is present, just rearranged (translocated - in your boy friend’s situation, there is a rearrangement between chromosomes 5 and 13) – this person is called a balanced translocation carrier and should have no health problems since all the chromosomal material needed is present and functioning properly.
However, when a person with a balanced chromosomal rearrangement forms eggs or sperm, some of the chromosomal material can be lost or duplicated so that the developing embryo has too much or not enough genetic material. This is what leads to an unbalanced translocation and usually a miscarriage. Occasionally however, that pregnancy can go on and the baby is often born with abnormalities and has mental retardation. The specific types of problems or birth defects would depend on the specific areas of the chromosomes that were lost or duplicated in the translocated chromosomes and what specific genes are located at these sites. For many unbalanced rearrangements (translocations) it is not possible to predict what abnormalities to expect; for others the medical literature may provide information.
If a parent has a balanced translocation, while they are at risk to miscarry somewhat more frequently than people who do not have a chromosomal translocation, they can have perfectly healthy pregnancies and children.
I do not know of any association between Parkinson disease and balanced chromosomal rearrangements.
If he has not already done so, I would recommend that you and your boy friend speak to the genetic counselor or a geneticist to discuss the specific chromosomal translocation that he has. He can locate a genetics center at the National Society of Genetic Counselors’ Resource Center website below.
Anne Matthews, RN, PhD
Associate Professor of Genetics
School of Medicine
Case Western Reserve University