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Disease Profile

Selective IgM deficiency

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset

All ages





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Selective immunoglobulin M deficiency; SIgMD


Congenital and Genetic Diseases; Immune System Diseases


Selective IgM deficiency (SIgMD) is a rare immune disorder in which a person has no immunoglobulin M (IgM) antibodies, or too little IgM, with normal levels of IgG and IgA antibodies.[1][2] IgM is the first antibody the immune system makes to fight a new infection.[3] Therefore, when a person does not have enough IgM, the body may have difficulty fighting infections. SIgMD can occur in infants, children, or adults.[1] The disorder may occur as a primary disorder (on its own) or more commonly, as a secondary disorder (associated with another underlying disease or condition). SIgMD may occur in association with some cancers, autoimmune diseases, allergic diseases, and gastrointestinal diseases.[2][4]

Symptoms of SIgMD may include repeated viral, bacterial, or fungal infections, such as ear infections, bronchitis, sinusitis, and pneumonia.[1] Infections may be life-threatening.[2] Repeated infections are common in infants with SIgMD.[1][4] In some people, diarrhea or a skin rash is the first symptom.[1] Others do not have symptoms specific to SIgMD and are diagnosed when being evaluated for another condition.[1][4] The diagnosis is made by blood tests showing low or absent IgM and normal levels of other antibodies, as well as diagnosing or ruling out underlying conditions that can cause low levels of IgM.[1]

The cause of SIgMD is still unclear.[1][2][4] SIgMD usually occurs in only one person in a family, but familial cases have occasionally been reported.[2] It may occur in some people with chromosome disorders such as 22q11.2 deletion syndrome.[2]

There are no official treatment recommendations since information about SIgMD is limited.[1] Treatment options depend on the severity of symptoms and whether a person has an associated underlying disease. Treatment may include prompt treatment of infections, taking measures to prevent infections, prophylactic antibiotics, and immune globulin therapy.[1][2]


Symptoms of selective IgM deficiency (SIgMD) may vary from person to person. Some people do not have any symptoms and are diagnosed by chance while being evaluated for another health problem. Others may experience mild to severe symptoms depending on the degree of the deficiency. Whether a person has primary or secondary SIgMD (associated with another underlying condition) also plays a role in the types of symptoms a person has, as they may also have symptoms of their underlying condition.

Most people with SIgMD, especially infants, have repeated bacterial and viral infections. Common infections in people with SIgMD include ear infections, sinus infections (sinusitis), bronchitis, and pneumonia. Some of these infections can result in sepsis, which can be life-threatening. Other types of infections that have been reported include smallpox and widespread molluscum contagiosum (a common skin condition in children). Children with SIgMD who are sick often may have failure to thrive and malnutrition.[1] Some people with SIgMD have skin rashes, wheezing, or diarrhea.[4] 

People with secondary SIgMD usually have too little IgM, rather than none at all. For this reason, their symptoms of SIgMD usually are more mild and may go away if the associated underlying condition improves.[1] Conditions that have been reported in association with SIgMD include:[1]


The underlying cause of selective IgM deficiency (SIgMD) is not yet known.[2] Several factors may play a role in causing SIgMD.[1] While some familial cases have been reported, no specific genes known to cause SIgMD have been found. SIgMD has been reported in people with various chromosome abnormalities, and most commonly in one that causes a chromosome disorder called 22q11.2 deletion syndrome.[2] More studies are needed to learn more about the possible causes of SIgMD.[5]


Treatment for selective IgM deficiency (SIgMD) varies because some people do not have symptoms, while others are at risk for serious infections. In general, fevers and infections should be evaluated and treated as soon as possible, especially if they seem to be getting worse.[1] People with no symptoms may not need specific treatment.

Measures should be taken to prevent infections whenever possible. Measures that have been recommended include:[1]

  • Having all recommended vaccinations.
  • Aggressive treatment of allergies such as asthma and allergic rhinitis (nasal allergies).
  • Prophylactic antibiotics for people who continue to get sick often.
  • Immune globulin therapy (IVIG) several researchers have reported a reduction in frequency and severity of infections in people with SIgMD treated with IVIG.[2]

People with SIgMD who experience new or different symptoms should be evaluated for an associated underlying disease or condition.[1] Symptoms of SIgMD may improve or go away if an associated disorder is treated or improves.[1]


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Organizations Providing General Support

      Learn more

      These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

      In-Depth Information

      • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
      • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
      • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
      • PubMed is a bibliographic database of biomedical journal literature. This database is maintained by the National Library of Medicine. Click on the link to search PubMed for relevant journal articles. Copy and paste the disease name and/or synonym(s) for your search. Please note that PubMed citations contain summaries but not the full text of the journal articles.


        1. Krishnaswamy G. Selective IgM deficiency. UpToDate. Waltham, MA: UpToDate; July 26, 2017; https://www.uptodate.com/contents/selective-igm-deficiency.
        2. Gupta S, Gupta A. Selective IgM Deficiency—An Underestimated Primary Immunodeficiency. Front Immunol. September, 2017; 8:Article 1056. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5591887/.
        3. Blood Test: Immunoglobulins (IgA, IgG, IgM). KidsHealth from Nemours. August, 2014; https://kidshealth.org/en/parents/test-immunoglobulins.html.
        4. Hussain I. Immunoglobulin M Deficiency. Medscape Reference. November 14, 2016; https://emedicine.medscape.com/article/137693-overview.
        5. Hassanein HA, Elbadry MI. Selective immunoglobulin M deficiency in an adult with miliary tuberculosis: A clinically interesting coexistence. A case report and review of the literature. International Journal of Mycobacteriology. March 2016; 5(1):106-110. https://va8ef7lf8s.search.serialssolutions.com/?sid=Entrez:PubMed&id=pmid:26928000.
        6. Chovancova Z, Kralickova P, Pejchalova A, Bloomfield M, Nechvatalova J, Vlkova M, Litzman J. Selective IgM Deficiency: Clinical and Laboratory Features of 17 Patients and a Review of the Literature. J Clin Immunol. August, 2017; 37(6):559-574. https://www.ncbi.nlm.nih.gov/pubmed/28730517.

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