WBR0104: Difference between revisions

Jump to navigation Jump to search
No edit summary
No edit summary
Line 21: Line 21:
|SubCategory=Renal
|SubCategory=Renal
|Prompt=A 40 year old woman with a history of recurrent urinary tract infections presents to her primary care physician with the gradual onset of increasing fatigue, swelling in her feet and anorexia.  She reports flank pain, and a recent decrease in urine volume.  Her pulse is 76, blood pressure is 145/110 and she has a respiratory rate of 16.  Physical exam is remarkable for bilateral solid masses that can be palpated during abdominal examination.  Tapping the lower back elicits sharp pain.  Laboratory studies are significant a creatinine of 2.3, and BUN of 20.  Which of the following is most likely true regarding the patient’s condition?
|Prompt=A 40 year old woman with a history of recurrent urinary tract infections presents to her primary care physician with the gradual onset of increasing fatigue, swelling in her feet and anorexia.  She reports flank pain, and a recent decrease in urine volume.  Her pulse is 76, blood pressure is 145/110 and she has a respiratory rate of 16.  Physical exam is remarkable for bilateral solid masses that can be palpated during abdominal examination.  Tapping the lower back elicits sharp pain.  Laboratory studies are significant a creatinine of 2.3, and BUN of 20.  Which of the following is most likely true regarding the patient’s condition?
|Explanation=This patient's form of ADPKD is caused by ADPKD1 mutations.  ADPKD1 is thought to encode a cellular membrane protein involved in assembly of the cilium.
|Explanation=Approximately 50% of people with this disease will develop end stage kidney disease and require dialysis or kidney transplantation. Progression to end stage kidney disease usually happens in the 4th to 6th decades of life. Autosomal dominant polycystic kidney disease occurs worldwide and affects about 1 in 400 to 1 in 1000 people.
Defects in two genes are thought to be responsible for ADPKD. In 85% of patients, ADPKD is caused by mutations in the gene PKD1 on chromosome 16 (TRPP1); in 15% of patients mutations in PKD2 (TRPP2) are causative.
 
This patient's form of ADPKD is caused by ADPKD1 mutations.  ADPKD1 is thought to encode a cellular membrane protein involved in assembly of the cilium.
|AnswerA=Caused by a defect in a calcium channel gene
|AnswerA=Caused by a defect in a calcium channel gene
|AnswerAExp=ADPKD2 is caused by defects in a calcium channel gene.  ADPKD2 has a later onset and is rarer than ADPKD1 mutations.
|AnswerAExp=ADPKD2 is caused by defects in a calcium channel gene.  ADPKD2 has a later onset and is rarer than ADPKD1 mutations.
Line 27: Line 30:
|AnswerBExp=This patient's form of ADPKD caused by ADPKD1 mutations.  ADPKD1 is thought to encode a cellular membrane protein involved in assembly of the cilium.
|AnswerBExp=This patient's form of ADPKD caused by ADPKD1 mutations.  ADPKD1 is thought to encode a cellular membrane protein involved in assembly of the cilium.
|AnswerC=Caused by autoantibodies against glomerular basement membrane
|AnswerC=Caused by autoantibodies against glomerular basement membrane
|AnswerCExp=Goodpasture's disease is caused by autoantibodies against glomerular basement membrane which would not cause renal masses.
|AnswerCExp=[[Goodpasture's disease]] is caused by autoantibodies against glomerular basement membrane which would not cause renal masses.
|AnswerD=Transmitted in an autosomal recessive fashion
|AnswerD=Transmitted in an autosomal recessive fashion
|AnswerDExp=Autosomal dominant polycystic kidney disease follows an autosomal dominant pattern of inheritance.
|AnswerDExp=Autosomal dominant polycystic kidney disease follows an autosomal dominant pattern of inheritance.
Line 33: Line 36:
|AnswerEExp=While a relationship between ADPKD and abdominal aortic aneurysms has been proposed, a study of 139 patients failed to detect any increased risk of abdominal aortic aneurysms (Torra et al). Instead, ADPKD is associated with cerebral berry aneurysms.  The incidence of these aneurysms climbs to greater than 20 percent for patients aged 60 and above.
|AnswerEExp=While a relationship between ADPKD and abdominal aortic aneurysms has been proposed, a study of 139 patients failed to detect any increased risk of abdominal aortic aneurysms (Torra et al). Instead, ADPKD is associated with cerebral berry aneurysms.  The incidence of these aneurysms climbs to greater than 20 percent for patients aged 60 and above.
|EducationalObjectives=The most common and more severe form of autosomal dominant polycystic kidney disease is caused by mutations in a cellular membrane protein involved in assembly of the cilium.
|EducationalObjectives=The most common and more severe form of autosomal dominant polycystic kidney disease is caused by mutations in a cellular membrane protein involved in assembly of the cilium.
|References=First Aid 2014 page 87
|References=First Aid 2014 page 87, Torra R, Nicolau C, Badenas C, et al. Abdominal aortic aneurysms and autosomal dominant polycystic kidney disease. J Am Soc Nephrol 1996; 7:2483.
|RightAnswer=B
|RightAnswer=B
|WBRKeyword=ADPKD, Autosomal dominant, Kidney, Renal,  
|WBRKeyword=ADPKD, Autosomal dominant, Kidney, Renal,
|Approved=Yes
|Approved=Yes
}}
}}

Revision as of 18:03, 22 March 2014

 
Author PageAuthor::William J Gibson
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Genetics
Sub Category SubCategory::Renal
Prompt [[Prompt::A 40 year old woman with a history of recurrent urinary tract infections presents to her primary care physician with the gradual onset of increasing fatigue, swelling in her feet and anorexia. She reports flank pain, and a recent decrease in urine volume. Her pulse is 76, blood pressure is 145/110 and she has a respiratory rate of 16. Physical exam is remarkable for bilateral solid masses that can be palpated during abdominal examination. Tapping the lower back elicits sharp pain. Laboratory studies are significant a creatinine of 2.3, and BUN of 20. Which of the following is most likely true regarding the patient’s condition?]]
Answer A AnswerA::Caused by a defect in a calcium channel gene
Answer A Explanation AnswerAExp::ADPKD2 is caused by defects in a calcium channel gene. ADPKD2 has a later onset and is rarer than ADPKD1 mutations.
Answer B AnswerB::Caused by a defect in the assembly of the cilium
Answer B Explanation AnswerBExp::This patient's form of ADPKD caused by ADPKD1 mutations. ADPKD1 is thought to encode a cellular membrane protein involved in assembly of the cilium.
Answer C AnswerC::Caused by autoantibodies against glomerular basement membrane
Answer C Explanation [[AnswerCExp::Goodpasture's disease is caused by autoantibodies against glomerular basement membrane which would not cause renal masses.]]
Answer D AnswerD::Transmitted in an autosomal recessive fashion
Answer D Explanation AnswerDExp::Autosomal dominant polycystic kidney disease follows an autosomal dominant pattern of inheritance.
Answer E AnswerE::Associated with abdominal aortic aneurysms
Answer E Explanation [[AnswerEExp::While a relationship between ADPKD and abdominal aortic aneurysms has been proposed, a study of 139 patients failed to detect any increased risk of abdominal aortic aneurysms (Torra et al). Instead, ADPKD is associated with cerebral berry aneurysms. The incidence of these aneurysms climbs to greater than 20 percent for patients aged 60 and above.]]
Right Answer RightAnswer::B
Explanation [[Explanation::Approximately 50% of people with this disease will develop end stage kidney disease and require dialysis or kidney transplantation. Progression to end stage kidney disease usually happens in the 4th to 6th decades of life. Autosomal dominant polycystic kidney disease occurs worldwide and affects about 1 in 400 to 1 in 1000 people.

Defects in two genes are thought to be responsible for ADPKD. In 85% of patients, ADPKD is caused by mutations in the gene PKD1 on chromosome 16 (TRPP1); in 15% of patients mutations in PKD2 (TRPP2) are causative.

This patient's form of ADPKD is caused by ADPKD1 mutations. ADPKD1 is thought to encode a cellular membrane protein involved in assembly of the cilium.
Educational Objective: The most common and more severe form of autosomal dominant polycystic kidney disease is caused by mutations in a cellular membrane protein involved in assembly of the cilium.
References: First Aid 2014 page 87, Torra R, Nicolau C, Badenas C, et al. Abdominal aortic aneurysms and autosomal dominant polycystic kidney disease. J Am Soc Nephrol 1996; 7:2483.]]

Approved Approved::Yes
Keyword WBRKeyword::ADPKD, WBRKeyword::Autosomal dominant, WBRKeyword::Kidney, WBRKeyword::Renal
Linked Question Linked::
Order in Linked Questions LinkedOrder::