NBME 21 Answers ↦
I'm confused that they said she appeared "normal". I thought AIS would mean the patient has very scant pubic hair / underarm hair. Wouldn't this be abnormal in a 17 year old? Should have Tanner stage 5 hair....
FA2020 (pg. 639) describes AIS as "Defect in androgen receptor resulting in normal-appearing female (46,XY DSD)" so I assume they're talking about general outwards appearance
You do get breasts because patient has build up of testosterone that is aromatized into estrogen. No axillary or pubic hair because that requires testosterone.
THX. SEE AIS (FA19 pg,625)
This makes sense, but I was thrown off by the "normal-appearing" b/c wouldn't AIS pts not have pubic hair?
They just say it's a normal appearing 17 year old girl; not that the external genitalia are normal appearing.
fa 19 pg 625
The above explanation is correct (disregarding the hard to read and unprofessional dialect) but just in case anyone was wondering:
chromatin-negative= Just a quick way of knowing it was a boy. The term applies to the nuclei of cells in normal males as well as those in individuals with certain chromosomal abnormalities
Turner syndrome patients are also chromatin negative as well though....
I didn't know a complication post-meningitis was lack of humor.
Ah, didn't read the last line. Yeah, that is taking it a bit far
yall are haters. this is the first explanation that has ever made sense to me
https://www.youtube.com/watch?v=yuXL-3eoB-o&t=77s Interesting syndrome watching this helped me to put it into real life perspective, interesting points they have no pubic hair/body hair, they apparently also dont smell, and breast size is usually increased...
How does chormatin-negative indicate a normal cell? Isn't chormatin just condensed DNA?
According to this paper most individuals with Turner Syndrome are chromatin negative: "One of the initial laboratory procedures used to confirm or rule out this diagnosis involves a sex chromatin determination from a buccal smear. Cells from the lining of the mouth are stained for the presence or absence of X-chromatin or Barr bodies, which represent a portion of an inactivated X chromosome. The typical Turner’s syndrome patient, who has 45 chromosomes and only one sex chromosome (an X), has no Barr bodies and is, therefore, X-chromatin negative.
This abnormal X-chromatin negative finding in the majority of Turner’s syndrome females is similar to the result found in a normal male, who also has only one X chromosome, and differs from the X-chromatin positive condition observed in the normal female, who has two X chromosomes. Occasionally, the patient with features of Turner’s syndrome is found to be X-chromatin positive."
i really hate haters this is awesome!
to add to the above, free testosterone is aromatized to estrogen leading to breast development
Is the free testosterone not creating male internal or external gentalia because of the defect in androgen receptors?