Background: Jacobsen Syndrome (JS) is a rare genetic syndrome caused by partial deletion of chromosome 11q. Clinical manifestations include physical and mental retardation, facial dysmorphism, heart defects and coagulopathies. Recurrent infections have been described in some of these patients, suggesting an underlying primary immunodeficiency as part of the syndrome.
Objective: to evaluate the immune status of 3 patients with JS.
Methods: Medical history of 3 patients was investigated for recurrent infections. Immune laboratory analyses included: blood count with differential, Immunoglobulin levels, specific antibodies to different vaccines, Lymphocyte sub-populations measured by flow-cytometry, T cell diversity, T cell response to mitogens and T cell receptor excision circle (TREC) levels.
Results: The 3 patients had suffered recurrent bacterial and viral infections since early childhood with respiratory, ophthalmic, ear and skin involvement. All 3 patients had mild lymphopenia. Two patients had hypogammaglobulinemia and poor specific antibodies response to most of the vaccines received. These 2 patients had low levels of CD4+ T cells and NK cells as well. However, T cell lymphocyte response to mitogens was essentially normal. TREC levels were low in one patient.
Conclusions: Some JS patients have a primary combined immunodeficiency as an integral part of their syndrome. Early immunological evaluation and appropriate treatment could prevent recurrent infections and associated complications in these patients.
