Wednesday, July 30, 2014
Inherited Disorders and Birth Defects
My daughter was born in 1991. She is missing part of chromosome #10. Could this be due to alkaline exposure to her great grandfather in a gold mine? P.S. Other relatives affected.
A deletion (a missing part) is caused by a chromosome break and then a loss of genetic material. It can occur anywhere along the chromosome and can occur with any chromosome. In the case of your daughter, you describe a deletion of chromosome 10. What types of problems are seen - the phenotype - would depend on what genes were located on the part of the chromosome that was missing and how much of the chromosome material was missing. Chromosome abnormalities, including deletions, usually lead to changes in growth - usually small, a possibility of major birth defects, often changes in facial features (dysmorphic features) and developmental delay or mental retardation.
There are data that have found that some exposures such as chemotherapy drugs, chemicals and radiation can cause damage to the chromosomes in sperm or eggs. So a man exposed to one of these agents could have a child with a chromosome abnormality.
If there are other family members who are also affected, it may be that your daughter’s great grandfather had a balanced chromosome rearrangement that has been passed on to other generations. In this case, people who inherited the balanced chromosome rearrangement would have no health problems, but they would have an increased chance to have children who have an unbalanced chromosome abnormality.
The only way to know if your daughter’s chromosome deletion is inherited is to look at you and your spouse’s chromosomes to see if one of you is a carrier of a balanced rearrangement that involves chromosome #10. If you or your spouse do not have a balanced chromosome rearrangement, then it is very unlikely that your daughter’s chromosome deletion is due to her great grandfather’s exposure to alkaline.
I would highly recommend that you talk to a geneticist or genetic counselor. They would be able to discuss with you whether or not testing you or other family members would be helpful. I would recommend that you talk to your doctor about being referred to a genetics center or you can find one near you at the National Society of Genetic Counselors website listed below.
Anne Matthews, RN, PhD
Associate Professor of Genetics
School of Medicine
Case Western Reserve University