What is X-linked hyper IgM syndrome?
X-linked hyper IgM syndrome is a condition that affects the immune system and occurs almost exclusively in males. People with this disorder have abnormal levels of proteins called antibodies or immunoglobulins. Antibodies help protect the body against infection by attaching to specific foreign particles and germs, marking them for destruction. There are several classes of antibodies, and each one has a different function in the immune system. Although the name of this condition implies that affected individuals always have high levels of immunoglobulin M (IgM), some people have normal levels of this antibody. People with X-linked hyper IgM syndrome have low levels of three other classes of antibodies: immunoglobulin G (IgG), immunoglobulin A (IgA), and immunoglobulin E (IgE). The lack of certain antibody classes makes it difficult for people with this disorder to fight off infections. Individuals with X-linked hyper IgM syndrome begin to develop frequent infections in infancy and early
