Thursday, November 27, 2014
Inherited Disorders and Birth Defects
Translocted chromosomes 2 and 4
My husband and I just lost a baby girl right after birth. She was born at 39 wks and weighed only 4.4 lbs. She had many birth defects and other problems. They did gentic tests on her and found that she had traslocated chromosomes in her 2 and 4 chromosomes. She was missing some in 4 and had extra in 2. We have two healthy children and have had 5 misscarriages. Could this be inheirted or not? we want another baby so bad, but are scared to even try later. We only lost her 2 wks ago today. Please help.
First, please accept my deepest sympathy on the death of your daughter. This is such a difficult time. From your description, it appears that your daughter had an unbalanced chromosomal translocation.
A translocation occurs when two pieces of chromosomes break off and switch places with each other. If all the chromosomal material is present, but has been rearranged (switched places), this is called a balanced translocation. This person should have no health problems since all the chromosomal material needed is present and functioning properly. There is no way to tell whether or not a person has one of these rearrangements unless you look at his or her blood to examine the chromosomes.
An unbalanced translocation is when some of the chromosomal material that was switched is lost or duplicated when the chromosomes broke and the switch took place – then there is extra and / or missing genetic information. This usually leads to miscarriages. However, if the pregnancy does not miscarry, then there are usually birth defects and cognitive problems such as learning disabilities, mental retardation and autism. This sounds like what may have happened in your daughter’s case where pieces of chromosomes 4 was lost and chromosome 2 had extra genetic material leading to her birth defects.
Unbalanced translocations can be inherited from a mother or father who has a balanced translocation. The only way to know if you are carrier of a balanced chromosomal translocation is to have your blood tested.
I would recommend that you speak to a geneticist or genetic counselor to discuss this in detail. They will be able to arrange to have your blood tested to look at the chromosomes if that has not yet been done. They can also discuss your concerns about pregnancies in the future. You can find a genetics center near you through the National Society of Genetic Counselors’ Resource Center at the website below.
Anne Matthews, RN, PhD
Associate Professor of Genetics
School of Medicine
Case Western Reserve University