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Old 12-15-2011
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Question thumbs appear signifcantly hypoplastic !

A 27-year-old mother brings her 4-year-old son to the pediatric outpatient clinic for evaluation. She is concerned because he has been more fatigued than usual over the last week. Two weeks ago, the child was taken to the emergency room for marked fatigue. He was later discharged with a diagnosis of a viral upper respiratory tract infection. At that time, the child was treated with diphenhydramine. When further questioned about the patient’s past medical history, the mother comments that her son has fallen sick more frequently than usual this past year and that he seems to bruise more easily than other children. On exam, vital signs are: temperature 37.6° C, pulse 110/min, respirations 30/min, and blood pressure 107/70 mmHg. The child is pallorous and noticeably lethargic. Height and head circumference are at the 5th percentile for his age. Conjunctival pallor is present. On musculoskeletal exam, both thumbs appear signifcantly hypoplastic. Skin exam reveals multiple petechiae on patient’s trunk and extremities. A complete blood count reveals a WBC count of 2,100/mm3, hemoglobin 6.7 g/dL, and platelets of 87,000/mm3. A peripheral blood smear reveals normocytic, normochromic erythrocytes.
What is the most likely mechanism underlying this disease?

A. Viral destruction of bone marrow progenitors
B. A defect in DNA repair
C. Peripheral destruction of erythrocytes
D. Decreased hemoglobin production
E. Autoimmune
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Old 12-16-2011
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its FANCONI'S ANEMIA....hypoplastic thumbs and congenital pan cytopenia....

so answer is B.defect in dna repair!!!
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Old 12-16-2011
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Yep Hypophalangeal thumb + bruising + infections

Fanconi's Anemia=Answer is B dna repair defect.

(Note:If triphalangeal thumb think Diamond Blackfan anemia)
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Old 12-16-2011
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B. A defect in DNA repair
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Old 12-17-2011
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The correct answer is B. A defect in DNA repair.

This patient is most likely ill from Fanconi anemia (FA). FA is a rare, autosomal recessive aplastic anemia. It is characterized by bone marrow failure, various congenital anomalies, and a greatly increased risk (up to 4000 times) for developing hematologic and solid malignancies. Some 13 genes have been implicated in the pathogenesis of FA. Mutations in these genes result in defective DNA repair, making chromosomes particularly susceptible to damage by DNA cross-linking agents such as mitomycin C. The other answer choices listed in Question 2 are not particularly associated with FA. Patients with FA typically demonstrate café-aulait spots, short stature, radial and/or thumb malformations, and genitourinary abnormalities. Cardiopulmonary and gastrointestinal abnormalities can also be seen. Signs and symptoms of pancytopenia such as petechiae and easy bruising due to thrombocytopenia, pallor and fatigue due to anemia, and recurrent infections due to leukopenia are also associated with FA. With regards to Question 1, Bloom syndrome is characterized by growth retardation, “bird-like” facies, and an abnormally high-pitched voice. Von Hippel Lindau (VHL) syndrome is characterized by hemangioblastomas, pheochromocytomas, and renal cell carcinomas. Werner syndrome is an autosomal recessive disorder of premature aging. Parvovirus B19 infection is associated with fifth disease. In certain patient populations, such as those with sickle cell anemia, Parvovirus B19 infection is associated with aplastic crises. It is also associated with a characteristic “slappedcheek” rash. Chromosome breakage analysis in the presence of DNA cross-linking agents is helpful in diagnosing FA. CBC shows pancytopenia with macrocytosis, which is reflected in an elevated erythrocyte mean corpuscular volume. A skeletal survey, abdominal ultrasound, and echocardiography should be performed to evaluate the presence and extent of any skeletal, renal, and/or cardiac abnormalities. Bone marrow aspirate and biopsy are helpful in evaluating marrow status. Though genetic testing for specific mutations is possible, such testing is not routinely employed in the diagnostic work-up for FA. Stem cell transplantation is the treatment of choice for FA. In cases where transplantation is not feasible, androgen administration has been found to be an effective therapy in a majority of patients. Treatment for pancytopenia may in-volve transfusion of red blood cells and platelets, as well as administration of granulocyte colony-stimulating-factor (G-CSF) for neutropenia.
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Hematology-, Step-2-Questions, Syndromes-Acronyms

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