WBR0065

Author	PageAuthor::William J Gibson
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Genetics, MainCategory::Microbiology
Sub Category	SubCategory::Oncology, SubCategory::General Principles, SubCategory::Infectious Disease
Prompt	[[Prompt::A 20 year old woman is contacted regarding an abnormal pap smear on her last annual physical. The smear showed dysplasia of squamous cells from the surface of the cervix. The degree of dysplasia is deemed CIN1. The molecular mechanism of oncogenesis of the causal organism is similar to the defect underlying which disease?]]
Answer A	AnswerA::Familial retinoblastoma
Answer A Explanation	AnswerAExp::Correct - see explanation.
Answer B	AnswerB::Familial adenomatous polyposis
Answer B Explanation	AnswerBExp::Incorrect - FAP is caused by mutations in the APC gene.
Answer C	AnswerC::Neurofibromatosis type I
Answer C Explanation	AnswerCExp::Incorrect - Neurofibromatosis is caused by mutations in the NF1 gene.
Answer D	AnswerD::Hereditary breast-ovarian cancer syndrome
Answer D Explanation	AnswerDExp::Incorrect - HBOC is caused by mutations in the BRCA1 and BRCA2 genes.
Answer E	AnswerE::Cowden’s sydrome
Answer E Explanation	AnswerEExp::Incorrect - Cowden’s syndrome is caused by mutations in the PTEN gene.
Right Answer	RightAnswer::A
Explanation	[[Explanation::This young woman has an abnormal pap smear as a result of infection with Human Papilloma Virus(HPV). HPV causes cervical dysplasia when the E6 and E7 proteins bind tumor suppressor proteins within the cell. E6 mediates the degradation of the tumor suppressor p53, which is mutated in Li-Fraumeni syndrome. E7 binds to and inactivates Rb which is mutated in familial retinoblastoma. Educational Objective: HPV causes oncogenesis when E7 binds to and inactivates Rb which is mutated in familial retinoblastoma. References: First Aid 2012 page 543 Tags: #Microbiology #Reproductive Educational Objective: References: ]]
Approved	Approved::Yes
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