Is Hyper IgM Syndrome hereditary?

Hyper IgM Syndrome is a rare genetic disorder that affects the immune system. It is characterized by a deficiency in the production of immunoglobulin (Ig) class-switching, specifically IgG, IgA, and IgE, while maintaining normal or elevated levels of IgM. This condition leads to an increased susceptibility to infections.

Is Hyper IgM Syndrome hereditary?

Yes, Hyper IgM Syndrome is hereditary. It is caused by mutations in the genes responsible for the class-switching process in B cells, which are a type of white blood cell involved in the immune response. These mutations are typically inherited in an X-linked recessive manner, meaning the gene mutation is located on the X chromosome.

Since males have one X and one Y chromosome, a single copy of the mutated gene is enough to cause the disorder. As a result, males are more commonly affected by Hyper IgM Syndrome. Females, on the other hand, have two X chromosomes, so they need to inherit two copies of the mutated gene to develop the condition. However, females with a single copy of the mutated gene may still exhibit milder symptoms or be asymptomatic carriers.

Genetic counseling is recommended for families with a history of Hyper IgM Syndrome to understand the risk of passing on the condition to future generations. Prenatal testing and carrier screening can help identify individuals who carry the mutated gene.