Hyperimmunoglobulinemia M syndrome (hyper IgM syndrome) is a rare form of primary immune insufficiency characterized by a sharp fall of concentrations of serum IgA; IgG and IgE in normal or elevated IgM. There are two genetic variants: X-linked and autosomic-recessive. Hyper IgM syndrome clinically manifests with early onset in the form of recurrent bacterial infections of respiratory and gastrointestinal tracts, hematological defects (neutropenia, thrombocytopenia, hemolytic anemia), higher occurrence of cancer, lymph node hyperplasia and hepatosplenomegaly. World literature reports 67 cases of hyper-IgM-syndrome. Molecular base of the X-linked disease is defective expression of molecule gp39 or CD40L resultant from mutations of gene CD40L mapped on the long X-chromosome arm. This entails defective activation of B-cell and transfer of immunoglobulin synthesis from IgM to other isotypes. In the literature about 40 mutations of the gene CD40L are described. Genetic examination of four boys with hyper IgM syndrome discovered that three of them had point mutations with replacement of one amino acid (glycine for glutaminic acid, triptofan for arginin, valin for alanin), one patient had doublication of 4 nucleotide pairs, one patient had reduced expression of CD40L on activated CD4 cells.
|Number of pages||5|
|Publication status||Published - 1998|
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