<prompt> Ataxia telangiectasia is characterised by all of the following except -Chronic sinopulmonary diseaseDecreased level of a-fetoproteinChromosomal breakageIgA deficiency  <response>: Ans. is b i.e., Decreased levels of a fetoproteins Ataxia telangiectasia o Ataxia Telangiectasia AT is an autosomal recessive disorder. o It is due to mutation of AT gene located on chromosome 11. o There is defective DNA repair that results in multiple chromosomal breaks. Clinical manifestations o Present in first decase of life. o Feature are : - i Oculocutaneous telengiectasia iiNeurological -4 Ataxia, dysahria, extensor plantar response, myoclonic jerks, areflexia, distal sensory deficity. iii Immunodeficeincy -- Thymic hypoplasia with cellular and humoral IgA and IgG2 immunodeficeincy. iv Recurrent pulmonary infections v Endocrine disorders --- Tye I DM vi Premature aging vii Malignancies Lymphoma, Hodgkins disease, acute T cell leukemia, breast cancer. and a-feto protein and carcino-embryonic antigen are increased 