Which of the following diseases is diagnosed with the help of the flowcytometry pattern?
(A) Bruton disease (B) Bare lymphocyte syndrome (C) Hyper IgM syndrome (D) Severe combined immunodeficiency disease
(C) Flow cytometry can rapidly and quantitatively measure several individual cell characteristics, but is mainly used to identify cellular antigens expressed by liquidtumors , those that arise from blood forming tissues. Hyper IgM syndrome - In this disorder the affected patients make IgM antibodies but are deficient in their ability to produce IgG, IgA and IgE antibodies. There is problem in Ig class switching. Approximately 70%of individuals with hyper lgM syndrome have the X linked form of the disease , caused by mutations in the gene coding CD40L located on Xq26. In remaining patients,the disease is inherited in an autosomal recessive pattern. Most of these patients have loss of function mutation involving either CD40 or enzyme called AID. So, B-cells can be detected by flowcytometryhaving low expression of CD40. Bruton's disease -In this disease, there is defect in B-cell tyrosine kinase enzyme. This leads to hypogammaglobulinemia. Bare lymphocyte syndrome- In this disorder, There is defect in MHC-2 molecule which is required for CD4 T-cell formation. SCID - This is both X-linked and autosomal recessive disorder.