WBR0114: Difference between revisions

Jump to navigation Jump to search
No edit summary
No edit summary
Line 20: Line 20:
|MainCategory=Genetics
|MainCategory=Genetics
|SubCategory=Endocrine, Reproductive
|SubCategory=Endocrine, Reproductive
|Prompt=A 15 year old girl is evaluated for failure to experience menarche.  The patient is 1.45 m (4’ 9”) tall has a broad chest, low hairline and a webbed neck.  Which of the following are associated with this patients condition?
|Prompt=A 15-year-old girl is evaluated for failure to experience menarche.  The patient is 1.45 m (4’ 9”) tall, has a broad chest, low hairline and a webbed neck.  Which of the following is most likely with this patient's condition?
|Explanation=The patient in this vignette is affected by Turner Syndrome.  Turner syndrome is caused by the lack of one copy of the X chromosome in females.  Patients therefore have the genotype 45,XO.  There are characteristic physical abnormalities, such as short stature, swelling, broad chest, low hairline, low-set ears, and webbed necksGirls with Turner syndrome typically experience gonadal dysfunction (non-working ovaries), which results in amenorrhea (absence of menstrual cycle) and sterility.  Turner Syndrome is also associated with cardiac abnormalities such as preductal coarction of the aorta, and bicuspid aortic valve.  Turner Syndrome is associated with lymphatic dysfunction causing lymphedema of the hands and feet as well as cystic hygromas which result in the webbed neck phenotype.  Patients can have renal abnormalities too, such as horseshoe kidney.
|Explanation=The patient in this vignette is affected by [[Turner syndrome]].  Turner syndrome is caused by the lack of one copy of the X chromosome in females.  Patients therefore have the genotype 45,XO.  There are characteristic physical abnormalities, such as short stature, swelling, broad chest, low hairline, low-set ears, and [[webbed neck]]sFemales with Turner syndrome typically experience gonadal dysfunction (non-working ovaries), which results in amenorrhea (absence of menstrual cycle) and sterility.  Turner syndrome is also associated with cardiac abnormalities such as preductal coarction of the aorta, and bicuspid aortic valve.  Turner syndrome is associated with lymphatic dysfunction causing lymphedema of the hands and feet as well as cystic hygromas which result in the webbed neck phenotype.  Patients can have renal abnormalities too, such as [[horseshoe kidney]].
|AnswerA=Increased LH, FSH, absence of functional SRY gene.
 
A patient with Turner syndrome and webbed neck is pictured below.
 
[[File:Neck Turner.JPG]]
|AnswerA=Increased LH, FSH, absence of functional SRY gene
|AnswerAExp=The absence of functional SRY gene would cause Swyer syndrome.  Swyer syndrome leads to phenotypic females with gonadal dysgenesis.
|AnswerAExp=The absence of functional SRY gene would cause Swyer syndrome.  Swyer syndrome leads to phenotypic females with gonadal dysgenesis.
|AnswerB=Decreased LH, FSH, lack of Barr body.
|AnswerB=Decreased LH, FSH, lack of Barr body
|AnswerBExp=While Turner syndrome is cause by the lack of a Barr body, these patients typically have increased FSH and LH.
|AnswerBExp=While Turner syndrome is cause by the lack of a Barr body, these patients typically have increased FSH and LH.
|AnswerC=Increased estrogen, preductal coarctation of the aorta.
|AnswerC=Increased estrogen, preductal coarctation of the aorta
|AnswerCExp=While preductal coarction of the aorta is associated with Turner Syndrome, the patients typically have decreased estrogen.
|AnswerCExp=While preductal coarction of the aorta is associated with Turner syndrome, the patients typically have decreased estrogen.
|AnswerD=Decreased estrogen,  horsehoe kidney.
|AnswerD=Decreased estrogen,  horsehoe kidney
|AnswerDExp= See explanation.
|AnswerDExp=Turner syndrome is associated with [[horshoe kidney]] and decreased estrogen due to gonadal dysgenesis.
|AnswerE=Decreased LH, FSH, infertile if untreated.
|AnswerE=Decreased LH, FSH, infertile if untreated
|AnswerEExp=Turner syndrome patients have increased FSH and LH due to low levels of estrogen.
|AnswerEExp=Turner syndrome patients have increased FSH and LH due to low levels of estrogen
|EducationalObjectives=Turner syndrome is associated with [[horshoe kidney]] and decreased estrogen due to gonadal dysgenesis.
|References=First Aid 2014 page 574 ; First Aid 2012 page 539
|References=First Aid 2014 page 574 ; First Aid 2012 page 539
For a detailed discussion of Turner syndrome, see: [[Turner syndrome history and symptoms]]
|RightAnswer=D
|RightAnswer=D
|WBRKeyword=Reproductive, Chromosome, Karyotype, Turner syndrome, Ovulation, Genetics,
|Approved=Yes
|Approved=Yes
}}
}}

Revision as of 11:14, 3 April 2014

 
Author PageAuthor::William J Gibson
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Genetics
Sub Category SubCategory::Endocrine, SubCategory::Reproductive
Prompt Prompt::A 15-year-old girl is evaluated for failure to experience menarche. The patient is 1.45 m (4’ 9”) tall, has a broad chest, low hairline and a webbed neck. Which of the following is most likely with this patient's condition?
Answer A AnswerA::Increased LH, FSH, absence of functional SRY gene
Answer A Explanation AnswerAExp::The absence of functional SRY gene would cause Swyer syndrome. Swyer syndrome leads to phenotypic females with gonadal dysgenesis.
Answer B AnswerB::Decreased LH, FSH, lack of Barr body
Answer B Explanation AnswerBExp::While Turner syndrome is cause by the lack of a Barr body, these patients typically have increased FSH and LH.
Answer C AnswerC::Increased estrogen, preductal coarctation of the aorta
Answer C Explanation AnswerCExp::While preductal coarction of the aorta is associated with Turner syndrome, the patients typically have decreased estrogen.
Answer D AnswerD::Decreased estrogen, horsehoe kidney
Answer D Explanation [[AnswerDExp::Turner syndrome is associated with horshoe kidney and decreased estrogen due to gonadal dysgenesis.]]
Answer E AnswerE::Decreased LH, FSH, infertile if untreated
Answer E Explanation AnswerEExp::Turner syndrome patients have increased FSH and LH due to low levels of estrogen
Right Answer RightAnswer::D
Explanation [[Explanation::The patient in this vignette is affected by Turner syndrome. Turner syndrome is caused by the lack of one copy of the X chromosome in females. Patients therefore have the genotype 45,XO. There are characteristic physical abnormalities, such as short stature, swelling, broad chest, low hairline, low-set ears, and webbed necks. Females with Turner syndrome typically experience gonadal dysfunction (non-working ovaries), which results in amenorrhea (absence of menstrual cycle) and sterility. Turner syndrome is also associated with cardiac abnormalities such as preductal coarction of the aorta, and bicuspid aortic valve. Turner syndrome is associated with lymphatic dysfunction causing lymphedema of the hands and feet as well as cystic hygromas which result in the webbed neck phenotype. Patients can have renal abnormalities too, such as horseshoe kidney.

A patient with Turner syndrome and webbed neck is pictured below.


Educational Objective: Turner syndrome is associated with horshoe kidney and decreased estrogen due to gonadal dysgenesis.
References: First Aid 2014 page 574 ; First Aid 2012 page 539

For a detailed discussion of Turner syndrome, see: Turner syndrome history and symptoms]]

Approved Approved::Yes
Keyword WBRKeyword::Reproductive, WBRKeyword::Chromosome, WBRKeyword::Karyotype, WBRKeyword::Turner syndrome, WBRKeyword::Ovulation, WBRKeyword::Genetics
Linked Question Linked::
Order in Linked Questions LinkedOrder::