WBR0770: Difference between revisions

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{{WBRQuestion
{{WBRQuestion
|QuestionAuthor={{Rim}}
|QuestionAuthor={{Rim}} (Reviewed by Will Gibson)
|ExamType=USMLE Step 1
|ExamType=USMLE Step 1
|MainCategory=Genetics
|MainCategory=Genetics
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|MainCategory=Genetics
|MainCategory=Genetics
|SubCategory=Oncology
|SubCategory=Oncology
|MainCategory=Genetics
|MainCategory=Genetics
|MainCategory=Genetics
|MainCategory=Genetics
|MainCategory=Genetics
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|MainCategory=Genetics
|MainCategory=Genetics
|SubCategory=Oncology
|SubCategory=Oncology
|Prompt=A 48 year old woman, previously healthy, presents to the physician's office for a left breast lump. She explains that she incidentally palpated the lump during showering. She does not complain of any pain or breast discharge. Following appropriate work-up, she is diagnosed with breast cancer. Genetic analysis shows that she is positive for BRCA1. When asked, the physician explains the normal function of BRCA1. What is the gene product of BRCA1?  
|Prompt=A 48-year-old woman, previously healthy, presents to the physician's office for a left breast lump she noticed on self-exam. She explains that she incidentally palpated the lump during showering. She does not complain of any pain or breast discharge. Following appropriate work-up, she is diagnosed with triple-negative breast cancer with ductal histology. Genetic analysis demonstrates a germline c.185delAG frameshift mutation in the BRCA1 gene. When asked, the physician explains the normal function of BRCA1. Which of the following best describes the molecular classification of the BRCA1 gene product?
|Explanation=BRCA1 and BRCA2 are tumor suppressor genes that are associated with breast cancer and ovarian cancer. BRCA genes encode DNA repair proteins normally. Hence, their loss in cancers lead to inhibition of synthesis of DNA repair proteins and facilitation of cancer growth.  
|Explanation=BRCA1 and BRCA2 are tumor suppressor genes that are associated with breast cancer and ovarian cancer. BRCA genes encode DNA repair proteins normally. Hence, their loss in cancers lead to inhibition of synthesis of DNA repair proteins and facilitation of cancer growth.  
Educational Objective:
BRCA tumor suppressor genes encode DNA repair proteins.
|AnswerA=DNA repair protein
|AnswerA=DNA repair protein
|AnswerAExp=BRCA1 and BRCA2 are tumor suppressor genes whose gene product is a DNA repair protein.
|AnswerAExp=BRCA1 and BRCA2 are tumor suppressor genes whose gene product is a DNA repair protein.
|AnswerB=Transcription factor
|AnswerB=Transcription factor
|AnswerBExp=Examples of genes that encode transcription factors are C-myc, L-myc, and N-myc, which are oncogenes associated with Burkitt's lymphoma, lung cancer, and neuroblastoma, respectively.  
|AnswerBExp=Examples of genes that encode transcription factors are C-myc, L-myc, and N-myc, which are oncogenes associated with Burkitt's lymphoma, lung cancer, and neuroblastoma, respectively.
|AnswerC=Tyrosine kinase
|AnswerC=Tyrosine kinase
|AnswerCExp=Examples of genes that encode tyrosine kinase are abl, HER/neu, and ret oncogenes, which are associated with CML, breast cancer, and MEN II syndromes, respectively.
|AnswerCExp=Examples of genes that encode tyrosine kinase are abl, HER/neu, and ret oncogenes, which are associated with CML, breast cancer, and MEN II syndromes, respectively.
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|AnswerE=Cytokine receptor
|AnswerE=Cytokine receptor
|AnswerEExp=An example of a gene that encodes a cytokine receptor is c-kit oncogene that is associated with gastrointestinal stromal tumors (GIST)
|AnswerEExp=An example of a gene that encodes a cytokine receptor is c-kit oncogene that is associated with gastrointestinal stromal tumors (GIST)
|EducationalObjectives=BRCA tumor suppressor genes encode DNA repair proteins.
|References=First Aid 2015 page 236
|RightAnswer=A
|RightAnswer=A
|WBRKeyword=breast, cancer, oncogene, tumor, suppressor, gene, genes, encode, product, protein, DNA, repair, BRCA1, BRCA2, lump
|WBRKeyword=Breast, Cancer, Breast cancer, Oncogene, Tumor, Tumor suppressor, Tumor Suppressor gene, Genetics, DNA, DNA repair, BRCA1, BRCA2
|Approved=No
|Approved=No
}}
}}

Revision as of 02:02, 21 January 2015
Author [[PageAuthor::Rim Halaby, M.D. [1] (Reviewed by Will Gibson)]]
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Genetics
Sub Category SubCategory::Oncology
Prompt [[Prompt::A 48-year-old woman, previously healthy, presents to the physician's office for a left breast lump she noticed on self-exam. She explains that she incidentally palpated the lump during showering. She does not complain of any pain or breast discharge. Following appropriate work-up, she is diagnosed with triple-negative breast cancer with ductal histology. Genetic analysis demonstrates a germline c.185delAG frameshift mutation in the BRCA1 gene. When asked, the physician explains the normal function of BRCA1. Which of the following best describes the molecular classification of the BRCA1 gene product?]]
Answer A AnswerA::DNA repair protein
Answer A Explanation AnswerAExp::BRCA1 and BRCA2 are tumor suppressor genes whose gene product is a DNA repair protein.
Answer B AnswerB::Transcription factor
Answer B Explanation AnswerBExp::Examples of genes that encode transcription factors are C-myc, L-myc, and N-myc, which are oncogenes associated with Burkitt's lymphoma, lung cancer, and neuroblastoma, respectively.
Answer C AnswerC::Tyrosine kinase
Answer C Explanation AnswerCExp::Examples of genes that encode tyrosine kinase are abl, HER/neu, and ret oncogenes, which are associated with CML, breast cancer, and MEN II syndromes, respectively.
Answer D AnswerD::GTPase
Answer D Explanation AnswerDExp::An example of a gene that encodes GTPase is ras oncogene that is associated with colon cancer.
Answer E AnswerE::Cytokine receptor
Answer E Explanation AnswerEExp::An example of a gene that encodes a cytokine receptor is c-kit oncogene that is associated with gastrointestinal stromal tumors (GIST)
Right Answer RightAnswer::A
Explanation [[Explanation::BRCA1 and BRCA2 are tumor suppressor genes that are associated with breast cancer and ovarian cancer. BRCA genes encode DNA repair proteins normally. Hence, their loss in cancers lead to inhibition of synthesis of DNA repair proteins and facilitation of cancer growth.

Educational Objective: BRCA tumor suppressor genes encode DNA repair proteins.
References: First Aid 2015 page 236]]

Approved Approved::No
Keyword WBRKeyword::Breast, WBRKeyword::Cancer, WBRKeyword::Breast cancer, WBRKeyword::Oncogene, WBRKeyword::Tumor, WBRKeyword::Tumor suppressor, WBRKeyword::Tumor Suppressor gene, WBRKeyword::Genetics, WBRKeyword::DNA, WBRKeyword::DNA repair, WBRKeyword::BRCA1, WBRKeyword::BRCA2
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