Which of the following is true about ataxia telangiectasia?
Ataxia telangiectasia Presence of immunosuppression Unable to walk properly (Ataxia)aabnormal gait Dilated touosity affecting blood vessels Increase in the risk of development of cancers Autosomal recessive condition Defect in DNA repair genes (more prone for malignancies) Deficiency of IgA & IgG2 antibodies Presence of amphicytes (nucleus is very big, 2.5times bigger than normal) The immunologic defects are of variable severity and may affect both B and T cells. The most prominent humoral immune abnormalities are defective production of isotype switched antibodies, mainly IgA and IgG2. The T cell defects, which are usually less pronounced, are associated with thymic hypoplasia. Patients experience upper and lower respiratory tract bacterial infections, multiple autoimmune phenomena, and increasingly frequent cancers with advancing age.The gene responsible for this disorder is located on chromosome 11 and encodes a protein called ATM (ataxia telangiectasia mutated) that is related structurally tophosphatidylinositol-3 (PI-3) kinase, but is a protein kinase.The ATM protein is a sensor of DNA damage (doublestrand breaks) and it activates p53 by phosphorylation, which in turn can activate cell cycle checkpoints and apoptosis in cells with damaged DNA. ATM has also been shown to contribute to the stability of DNA double-strand break complexes during V(D)J recombination. Because of these abnormalities in DNA repair, the generation of antigen receptors may be abnormal. In addition, defective DNA repair may lead to abnormalities in the DNA recombination events that are involved in antibody iso-type switching.
It is associated with normal immune function
Serum levels of IgA are increased
It is an autosomal recessive disease
There is absence of amphicytes in different organs
NEET 2018