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Gene Review

SEMA7A  -  semaphorin 7A, GPI membrane anchor (John...

Homo sapiens

Synonyms: CD108, CDw108, H-SEMA-K1, H-Sema-L, JMH, ...
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Disease relevance of SEMA7A

  • Previous work has shown that JMH is absent from complement-sensitive erythrocytes of patients with paroxysmal nocturnal hemoglobinuria (PNH); such cells have a broad defect in expression of phosphatidylinositol (PI)-linked proteins [1].
  • To investigate whether there are variations in the growth capacity of HIV in peripheral blood mononuclear cell (PMBC) preparations from different individuals, PBMC cultures prepared from 27 healthy donors were infected with the fresh HIV-1 isolates JH/3 or JMH/1 [2].
  • CR3 and CDw108 could not be seen on uninfected cells, but wre detectable on infected cells and virions [3].
  • A descriptive analysis was performed of malignant melanoma data ascertained by the University of Miami School of Medicine/Jackson Memorial Hospital (UM/JMH) Tumor Registry [4].

High impact information on SEMA7A

  • JMH is a high-frequency human erythrocyte blood group antigen [1].
  • A similar 76-Kd JMH protein was also identified on a human lymphoid T-cell line, HSB-2 [1].
  • CDw108, also known as the John-Milton-Hagen human blood group Ag, is an 80-kDa glycosylphosphatidylinositol (GPI)-anchored membrane glycoprotein that is preferentially expressed on activated lymphocytes and E. The molecular characteristics and biological function of the CDw108 were not clarified previously [5].
  • Radiation hybrid mapping indicated that the CDw108 gene was located in the middle of the long arm of chromosome 15 (15q23-24) [5].
  • The CDw108 mRNA was expressed in activated PBMCs as well as in the spleen, thymus, testis, placenta, and brain, but was not expressed in any other tissues tested [5].

Biological context of SEMA7A

  • These different phenotypes are caused by variations of the SEMA7A gene or seem to be generated by autoimmune-related or RBC lineage-specific mechanisms [6].
  • Following transfusion with three JMH-positive units, the patient's hematocrit increased from 20.7 percent to 32.1 percent [7].
  • STUDY DESIGN AND METHODS: The JMH antigen status was determined by serology, flow cytometry, and Western blot [6].
  • STUDY DESIGN AND METHODS: Murine monoclonal antibodies and human antibodies to JMH were used in hemagglutination, radioimmunoassay, and Western blot testing of red cells from two JMH-variant patients; antiserum from one of these patients was also used in biochemical studies [8].

Anatomical context of SEMA7A


Associations of SEMA7A with chemical compounds

  • Chromium-51-labeled JMH-positive cells which were weakly incompatible in vitro appeared to survive normally [7].

Analytical, diagnostic and therapeutic context of SEMA7A


  1. Isolation of the JMH antigen on a novel phosphatidylinositol-linked human membrane protein. Bobolis, K.A., Moulds, J.J., Telen, M.J. Blood (1992) [Pubmed]
  2. Variations in growth capacity of HIV in peripheral blood mononuclear cell preparations from different individuals. Yamada, O., Matsumoto, T., Sasoaka, R., Kurimura, T. AIDS (1990) [Pubmed]
  3. Acquisition of host cell-surface-derived molecules by HIV-1. Frank, I., Stoiber, H., Godar, S., Stockinger, H., Steindl, F., Katinger, H.W., Dierich, M.P. AIDS (1996) [Pubmed]
  4. Descriptive analysis of the tumor registry experience for malignant melanoma from 1977 to 1986 at the University of Miami School of Medicine/Jackson Memorial Hospital. Raub, W.A., Feun, L.G., Duncan, R.C., Moffat, F., Savaraj, N., Nemeth, A., Markoe, A. Cancer Detect. Prev. (1992) [Pubmed]
  5. Molecular cloning of a glycosylphosphatidylinositol-anchored molecule CDw108. Yamada, A., Kubo, K., Takeshita, T., Harashima, N., Kawano, K., Mine, T., Sagawa, K., Sugamura, K., Itoh, K. J. Immunol. (1999) [Pubmed]
  6. The molecular diversity of Sema7A, the semaphorin that carries the JMH blood group antigens. Seltsam, A., Strigens, S., Levene, C., Yahalom, V., Moulds, M., Moulds, J.J., Hustinx, H., Weisbach, V., Figueroa, D., Bade-Doeding, C., Deluca, D.S., Blasczyk, R. Transfusion (2007) [Pubmed]
  7. Anti-JMH identified in serum and in eluate from red cells of a JMH-negative man. Whitsett, C.F., Moulds, M., Pierce, J.A., Hare, V. Transfusion (1983) [Pubmed]
  8. JMH variants: serologic, clinical, and biochemical analyses in two cases. Mudad, R., Rao, N., Issitt, P.D., Roy, R.B., Combs, M.R., Telen, M.J. Transfusion (1995) [Pubmed]
  9. Characterization of the human leukocyte GPI-anchored glycoprotein CDw108 and its relation to other similar molecules. Angelisová, P., Drbal, K., Cerný, J., Hilgert, I., Horejsí, V. Immunobiology (1999) [Pubmed]
  10. Evidence that CDw108 membrane protein bears the JMH blood group antigen. Mudad, R., Rao, N., Angelisova, P., Horejsi, V., Telen, M.J. Transfusion (1995) [Pubmed]
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