G6PD deficiency is inherited in what is called an X-linked recessive manner. The gene that causes G6PD deficiency (G6PD) is located on the X chromosome. The X chromosome is one of the sex chromosomes, which help determine our biological gender. Women have two X chromosomes, while men have an X and a Y chromosome. This means that women have two copies of G6PD, while men only have one copy of G6PD. A man needs only one G6PD gene mutation to have symptoms of G6PD deficiency. A woman needs two G6PD gene mutations to have symptoms G6PD deficiency. Since this happens very rarely, women rarely have signs or symptoms of G6PD deficiency.
A woman can be a carrier for a G6PD gene mutation, meaning that she only has one mutation. She may or may not show symptoms of the condition. However, she has a 50% random chance of passing down that mutation to her children, regardless of the child’s gender. If a boy inherits the mutation, he will develop G6PD deficiency. If a girl inherits the mutation, she will be a carrier, like her mother. A man who has G6PD deficiency cannot pass down the gene mutation to his sons, but he will pass it down to all of his daughters. If the daughter inherits a mutation from her father and a mutation from her mother, she will also develop G6PD deficiency.
If you would like to learn more about the genetics of G6PD deficiency, or have it in your family, speak to your doctor about a referral to see a genetic counselor. In the U.S., you can find a genetic counselor near you by using the Find a Genetic Counselor Tool on the National Society of Genetic Counselors website.
Other Questions About Glucose-6-phosphate dehydrogenase (G6PD) deficiency
- Why does G6PD deficiency cause anemia?
- Who else in my family should have testing for G6PD deficiency?
- What type of sample should be taken for G6PD deficiency genetic testing?
- What treatment can help the symptoms of G6PD deficiency from getting worse?
- What is the usual abbreviation for G6PD deficiency?
