{"id":2109,"date":"2009-12-30T20:55:21","date_gmt":"2009-12-31T01:55:21","guid":{"rendered":"http:\/\/insidesurgery.com\/?p=2109"},"modified":"2013-08-17T16:46:54","modified_gmt":"2013-08-17T20:46:54","slug":"ataxiatelangiectasia-louisbar-syndrome","status":"publish","type":"post","link":"https:\/\/insidesurgery.com\/2009\/12\/ataxiatelangiectasia-louisbar-syndrome\/","title":{"rendered":"Ataxia-telangiectasia (Louis-Bar Syndrome)"},"content":{"rendered":"
Pathophysiology<\/strong><\/p>\n 1)<\/strong> genetic disorder, usually presenting at age 0-10 years 2)<\/strong> cerebellar malfunctioning 3)<\/strong> strong association with cancer 4)<\/strong> oculocutaneous telangiectasia 5)<\/strong> malfunctioning immune system<\/p>\n Signs and Symptoms<\/strong><\/p>\n 1)<\/strong> spider angiomas 2)<\/strong> cerebellar dysfunction with staggering-type gait 3)<\/strong> growth retardation 4)<\/strong> recurrent pulmonary infections 5)<\/strong> nystagmus 6)<\/strong> linear telangiectasias initially appearing on bulbar conjunctiva 7)<\/strong> telangiectasias progress to butterfly pattern on ears, eyelids, and cheeks 8)<\/strong> dysarthria 9)<\/strong> myoclonic jerks 10)<\/strong> areflexia 11)<\/strong> sensory deficits 12)<\/strong> premature aging<\/p>\n Characteristic Test Findings<\/strong><\/p>\n Laboratory<\/em> – 1)<\/strong> decreased lymphocyte count 2)<\/strong> antibodies to insulin receptor 3)<\/strong> presence of alpha fetoprotein 4)<\/strong> presence of carcinoembryonic antigen 5)<\/strong> decreased number of T cells 6)<\/strong> decreased levels of IgE and IgA<\/p>\n Histology\/Gross Pathology<\/strong><\/p>\n 1)<\/strong> loss of Purkinje , basket, and granule cells in cerebellar cortex 2)<\/strong> loss of anterior horn cells in spinal cord and dorsal columns<\/p>\n Associated Conditions<\/strong><\/p>\n 1)<\/strong> lymphomas (especially Hodgkin’s lymphoma) 2)<\/strong> leukemia 3)<\/strong> gastric cancer 4)<\/strong> brain tumors 5)<\/strong> breast cancer 6)<\/strong> hypoplastic thymus 7)<\/strong> diabetes with severe insulin resistance 8)<\/strong> ovarian agenesis 9)<\/strong> infertility 10)<\/strong> hypersensitive to ionizing radiation 11)<\/strong> decreased pituitary functioning 12)<\/strong> adrenal cortical hyperplasia<\/p>\n Biochemistry<\/strong><\/p>\n 1)<\/strong> deficient functioning of both B and T cells 2)<\/strong> defective nuclear phophoprotein cannot respond to DNA damage<\/p>\n Inheritance\/Epidemiology<\/strong><\/p>\n 1)<\/strong> autosomal recessive 2)<\/strong> defective ATM gene is on chromosome 11 (11q22-q23) 3)<\/strong> occurs in 1\/50,000 4)<\/strong> heterozygotes have increased risk of breast cancer<\/p>\n Treatment<\/strong><\/p>\n 1)<\/strong> avoidance of live vaccines 2)<\/strong> avoidance of blood products with T cells 3)<\/strong> avoidance of exogenous radiation 4)<\/strong> consider prophylaxis for Pneumocystis carinii<\/em> with trimethoprim-sulfamthoxazole<\/p>\n Tips for USMLE<\/strong><\/p>\n 1)<\/strong> incidence of cancer is increased 100-fold 2)<\/strong> ataxia-telangiectasia is both a T cell and B cell problem 3)<\/strong> DNA damage cannot be repaired<\/p>\n","protected":false},"excerpt":{"rendered":" Pathophysiology 1) genetic disorder, usually presenting at age 0-10 years 2) cerebellar malfunctioning 3) strong association with cancer 4) oculocutaneous telangiectasia 5) malfunctioning immune system Signs and Symptoms 1) spider angiomas 2) cerebellar dysfunction with staggering-type gait 3) growth retardation 4) recurrent pulmonary infections 5) nystagmus 6) linear telangiectasias initially appearing on bulbar conjunctiva 7) […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[5080,5151,5108,63],"tags":[757,759,755,758,760,754,756],"yoast_head":"\n