This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
[{'content': 'Ataxia telangiectasia is characterised by all of the following except – \nSelect and explain. \nA. Chronic sinopulmonary disease, B. Decreased level of α–fetoprotein, C. Chromosomal breakage, D. IgA deficiency', 'role': 'user'}, {'content': 'Answer: B \nExplanation: "Persistence of very high levels of oncofetal proteins, including alpha-fetoproteins and carcinoembryonic antigens is of diagnostic value" - Harrison\n\nAtaxia telangiectasia \n\nAtaxia Telangiectasia (AT) is an autosomal recessive disorder.\nIt is due to mutation of AT gene located on chromosome 11.\nThere is defective DNA repair that results in multiple chromosomal breaks.\n\nClinical manifestations\n\nPresent in the first decade of life.\nFeature are : -\n\n\nOculocutaneous telengiectasia\nNeurological → Ataxia, dysarthria, extensor plantar response, myoclonic jerks, are flexia, distal sensory deficit.\nImmunodeficiency →Thymic hypoplasia with cellular and humoral (IgA and IgG2) immunodeficiency.\nRecurrent pulmonary infections\nEndocrine disorders → Type I DM\nPremature ageing\nMalignancies → Lymphoma, Hodgkin\'s disease, acute T cell leukemia, breast cancer.\n\n\nα-feto protein and carcino-embryonic antigen are increased', 'role': 'assistant'}]