Alternative titles; symbols
ORPHA: 1572; DO: 0081148;
| Location | Phenotype |
Phenotype MIM number |
Inheritance |
Phenotype mapping key |
Gene/Locus |
Gene/Locus MIM number |
|---|---|---|---|---|---|---|
| 11q12.2 | ?Immunodeficiency, common variable, 5 | 613495 | Autosomal recessive | 3 | MS4A1 | 112210 |
A number sign (#) is used with this entry because of evidence that this form of common variable immunodeficiency (CVID), referred to here as CVID5, is caused by homozygous mutation in the CD20 gene (MS4A1; 112210) on chromosome 11q13. One such patient has been reported.
For a general description and a discussion of genetic heterogeneity of common variable immunodeficiency, see CVID1 (607594).
Kuijpers et al. (2010) reported a Turkish girl, born of consanguineous parents, who developed recurrent respiratory infections and bronchopneumonia at age 2 years. At onset, she had low IgG and low IgA levels. During a follow-up of 4 years, she showed normal IgM and IgA levels, but low IgG levels. Laboratory studies showed normal numbers of B cells, but persistent hypogammaglobulinemia, reduced circulating memory B cells, and complete lack of surface CD20 on B cells. There was also a decreased frequency of somatic hypermutations in IgG heavy chain genes and impaired T cell-dependent or -independent IgG antibody formation in vitro. However, patient B cells showed normal proliferation and formation of IgM, indicating intact early development of B cells. In addition, an IgG response could be generated after repeated booster immunization of tetanus toxoid in vivo. B cells of each parent had about 50% CD20 expression compared to controls.
In a Turkish girl with common variable immunodeficiency-5, Kuijpers et al. (2010) identified a homozygous mutation in the MS4A1 gene (112210.0001).
Kuijpers et al. (2010) found that Cd20-null mice had severely impaired T-cell independent antipolysaccharide antibody responses.
Kuijpers, T. W., Bende, R. J., Baars, P. A., Grummels, A., Derks, I. A. M., Dolman, K. M., Beaumont, T., Tedder, T. F., van Noesel, C. J. M., Eldering, E., van Lier, R. A. W. CD20 deficiency in humans results in impaired T cell-independent antibody responses. J. Clin. Invest. 120: 214-222, 2010. [PubMed: 20038800] [Full Text: https://doi.org/10.1172/JCI40231]