USMLE Forum Archives - USMLE Step 1 - Pathology 6
Pathology 6
TheOne - 09-25-06 13:19
A 2-year-old child presents to the pediatrician with hematuria. Examination reveals hypertension and an abdominal mass. A tumor is localized to the right kidney and biopsy reveals a stroma containing smooth and striated muscle, bone, cartilage, and fat, with areas of necrosis. The gene for this disorder has been localized to which of the following chromosomes?
A. 5
B. 11
C. 13
D. 17
E. 22
TheOne - 09-25-06 13:19
A 2-year-old child presents to the pediatrician with hematuria. Examination reveals hypertension and an abdominal mass. A tumor is localized to the right kidney and biopsy reveals a stroma containing smooth and striated muscle, bone, cartilage, and fat, with areas of necrosis. The gene for this disorder has been localized to which of the following chromosomes?
A. 5
B. 11
C. 13
D. 17
E. 22
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#4
Re: Pathology 6 Youngdoctor - 09-27-06 00:37 Wi11ms Tumor chromosome 11
Good explanation.I am happy about this.
#5
Re: Pathology 6
TheOne - 09-27-06 21:50 Very good
Explanation: The correct answer is B. This is a tough two-step style question. You first needed to make the diagnosis, and then you needed to recall the localization of this particular disease to a specific chromosome. In this case, everything in the vignette leads you to a diagnosis of Wilms' tumor. Wilms' tumor occurs in children and typically presents with an abdominal mass as well as with hypertension, hematuria, nausea, and intestinal obstruction. Because the tumor is derived from mesonephric mesoderm, it can include mesodermal derivatives such as bone, cartilage, and muscle. The Wilms' tumor suppressor gene (WT-1) has been localized to chromosome 11 (11p). The remaining answer choices provide us the opportunity to discuss some other known relationships between genes and disease. This is a topic of intense research that is likely to become more and more emphasized on the USMLE examinations. Chromosome 5 (choice A) is the site of the tumor suppressor gene APC, which is involved in the pathogenesis of colon cancer and familial adenomatous polyposis. Chromosome 13 (choice C) is the site of the tumor suppressor gene for retinoblastoma and osteosarcoma (Rb) as well as the BRCA-2 gene for breast cancer. Chromosome 17 (choice D) is the site of p53 (involved in most human cancers), NF-1 (neurofibromatosis type I), and BRCA-1 (breast and ovarian cancer). Chromosome 22 (choice E) is home to the NF-2 gene, which is involved in neurofibromatosis type II.
#6
Re: Pathology 6 galaxy - 05-27-10 18:48 the explanation correlates with wilms tumor or nephroblastoma ... hence a suppression of gene on chromosome 11 is expected....
#7
Re: Pathology 6 babbu5508 - 06-21-10 14:43 The WT1 gene located at 11p13 was identified as a cause of wilm's tumour or nephroblastoma in most of the cases............
#8
Re: Pathology 6 bingousmle - 06-30-10 22:44 hematuria.hypertension and an abdominal mass which has smooth and striated muscle, bone, cartilage, and fat, with areas of necrosis.
B. 11
#11
Re: Pathology 6 babbu5508 - 09-24-10 06:51 stroma containing smooth and striated muscle, bone, cartilage, and fat, with areas of necrosis...indicates a wilm's tumour...
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