Hyper-IgM syndrome type 5

Editor-In-Chief: Prab R Tumpati, MD
Obesity, Sleep & Internal medicine
Founder, WikiMD Wellnesspedia &
W8MD's weight loss doctor NYC
Philadelphia GLP-1 weight loss and GLP-1 clinic NYC

Hyper-IgM syndrome type 5
IgM structure
Synonyms	CD40 deficiency
Pronounce	N/A
Specialty	N/A
Symptoms	Recurrent infections, low levels of immunoglobulins except IgM
Complications	Autoimmune disease, liver disease, cancer
Onset	Usually in infancy
Duration	Lifelong
Types	N/A
Causes	Genetic mutations in the CD40 gene
Risks	Family history of the condition
Diagnosis	Genetic testing, measurement of immunoglobulin levels
Differential diagnosis	Other types of Hyper-IgM syndrome, Common variable immunodeficiency
Prevention	N/A
Treatment	Immunoglobulin replacement therapy, hematopoietic stem cell transplantation
Medication	N/A
Prognosis	Variable, dependent on treatment and complications
Frequency	Rare
Deaths	N/A

Hyper-IgM syndrome type 5

Hyper-IgM syndrome type 5 is a rare immunodeficiency disorder characterized by a decreased ability to switch from making antibodies known as immunoglobulin M (IgM) to antibodies of other types. This condition is one of several types of hyper-IgM syndrome, each of which is caused by a mutation in a different gene. People with hyper-IgM syndrome type 5 have low numbers of T cells and B cells, which are both types of immune system cells.

Causes

Hyper-IgM syndrome type 5 is caused by mutations in the Ungene gene. This gene provides instructions for making an enzyme called uracil-DNA glycosylase, which is involved in repairing damaged DNA. Mutations in the UNG gene lead to a shortage of functional uracil-DNA glycosylase, which impairs the ability of B cells to switch from making IgM antibodies to making other types of antibodies.

Symptoms

People with hyper-IgM syndrome type 5 have an increased susceptibility to infections, especially those caused by Pneumocystis jirovecii, a type of fungus. They may also have an increased risk of developing autoimmune disorders, in which the immune system attacks the body's own tissues and organs.

Diagnosis

Diagnosis of hyper-IgM syndrome type 5 is based on the presence of characteristic symptoms, a detailed patient history, a thorough clinical evaluation, and a variety of specialized tests. These tests may include blood tests to measure levels of different types of antibodies, genetic testing to identify mutations in the UNG gene, and tests to assess the function of the immune system.

Treatment

Treatment of hyper-IgM syndrome type 5 is focused on managing the symptoms and preventing complications. This may include antibiotics to treat infections, immunoglobulin therapy to boost the immune system, and in some cases, a stem cell transplant.

See also

• Hyper-IgM syndrome
• Immunodeficiency
• Antibodies
• T cells
• B cells
• Ungene
• Pneumocystis jirovecii
• Autoimmune disorders