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21/12/2019

Which set of genetic defects would cause Hyper IgM Syndrome?

Which set of genetic defects would cause Hyper IgM Syndrome?

X-linked hyper IgM syndrome is caused by an altered gene on the X chromosome and is inherited in an X-linked recessive pattern.

What does an elevated IgM indicate?

IgM. High levels of IgM can mean macroglobulinemia, early viral hepatitis, mononucleosis, rheumatoid arthritis, kidney damage (nephrotic syndrome), or a parasite infection is present.

What is CD40 deficiency?

CD40 ligand (CD40L) deficiency or X-linked Hyper-IgM syndrome is a severe primary immunodeficiency caused by mutations in the CD40L gene. Despite currently available treatments, CD40L-deficient patients remain susceptible to life-threatening infections and have poor long term survival.

What causes IgM antibodies?

Immunoglobulin M: Your body makes IgM antibodies when you are first infected with new bacteria or other germs. They are your body’s first line of defense against infections. When your body senses an invader, your IgM level will rise for a short time.

What does IgM do in the body?

Immunoglobulin G (IgG), the most abundant type of antibody, is found in all body fluids and protects against bacterial and viral infections. Immunoglobulin M (IgM), which is found mainly in the blood and lymph fluid, is the first antibody to be made by the body to fight a new infection.

What cells produce IgM antibodies?

IgM immunoglobulins are produced by plasma cells as part of the body’s adaptive humoral immune response against a foreign pathogen. Resting mature yet naive, B lymphocytes express IgM as a transmembrane antigen receptor that functions as part of the B-cell receptor (BCR).

Is IgM deficiency serious?

IgM is the first antibody the immune system makes to fight a new infection. Therefore, when a person does not have enough IgM, the body may have difficulty fighting infections. SIgMD can occur in infants, children, or adults.

What does it mean when your IgM is low?

Low levels of IgM may mean your immune system is not working optimally. Because this antibody helps provide protection against bacteria and viruses, having low IgM levels has been associated with a higher risk of recurring infections [8].

Where do IgM antibodies come from?

Do plasma cells secrete IgM?

Short-lived plasma cells secrete nonmutated IgM or IgG, peak in numbers at days 8–10 postimmunization, and are found primarily at the B/T zone borders of the red pulp in the spleen or in the medullary cords of the lymph nodes.

What are the symptoms of hyper IgM syndrome type 5?

HYPER IGM SYNDROME TYPE 5. This form is also known as uracil-DNA-glycosylase deficiency. Affected individuals develop signs and symptoms that are similar to those seen in hyper IgM syndrome type 2 including a susceptibility to bacterial infections and lymphoid hyperplasia, and a lack of opportunistic infections.

Are there any autosomal recessive forms of hyper IgM?

In autosomal recessive hyper-IgM syndrome with CD40 mutation, manifestations are similar to those of the X-linked form. At least 4 autosomal recessive forms involve a B-cell defect.

What happens to B cells in hyper IgM syndrome?

In X-linked hyper-IgM syndrome, T cells lack functional CD40 ligand and cannot signal B cells to switch. Thus, B cells produce only IgM; IgM levels may be normal or elevated. Patients with the X-linked form may have severe neutropenia and often present during infancy with Pneumocystis jirovecii pneumonia.

What are the treatment options for hyper IgM syndrome?

Treatment of hyper-IgM syndrome usually includes immune globulin replacement therapy. Patients with the X-linked form or CD40 mutations are given prophylactic trimethoprim/sulfamethoxazole to prevent P. jirovecii infection, and environmental precautions are taken to reduce the risk of Cryptosporidium infection (see Gastroenteritis : Prevention ).