Monday, September 1, 2014
Inherited Disorders and Birth Defects
My child is a G6PD deficient. I was wondering if it really runs in the family? How did it occur in my child when in fact none in both of our families with my husband had that condition? I read some articles which states that women often are carriers while men are affected. Thank you.
As you know, G6PD deficiency (Glucose-6-Phosphate Dehydrogenase Deficiency) is a genetic disorder that is caused by a defect in the gene that codes for an enzyme (called G6PD) that leads to red blood cells being broken down too soon and the person has anemia.
It is an X-linked genetic disorder - that is, the gene change (mutation) in the gene G6PPD, is located on the X chromosome. It affects boys more often because boys only have one X chromosome, which they inherit from their mothers. Boys inherit a Y chromosome from their fathers. Mothers are carriers for this gene mutation. Mothers are usually not affected because they have 2 X chromosomes, one X chromosome has a normal G6PD gene while the other has the changed gene (mutated gene). The normal G6PD gene functions enough so that mothers do not have any problems. Problems happen when there is a boy because he has only 1 X chromosome (he is a boy because of the Y chromosome).
Because you mentioned that there were no other family members affected on your side of the family, it could be that the gene change occurred in your son for the first time. However, you could be a carrier for G6PD deficiency and would not know it. It would be important to know if you are a carrier in case you decide to have more children. If you are a carrier, then there is a 1 out of 2 chance (50%) that a son could be affected. Also, you would have a 1 out of 2 chance (50%) to have a daughter who is a carrier like you.
G6PD deficiency is very common among African Americans. It is also more common in people with Mediterranean and Asian ancestry.
I would recommend that you talk to a genetic counselor to discuss G6PD deficiency. You can ask your doctor about a referral to a genetics center or you can locate a center near you 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