need help with your account or subscription? click here to email us (or see the contact page)
join telegramNEW! discord
jump to exam page:
search for anything ⋅ score predictor (โ€œpredict me!โ€)

Retired NBME 16 Answers

nbme16/Block 1/Question#25 (reveal difficulty score)
A 1-year-old boy is brought to the physician ...
Inability to produce melanin ๐Ÿ” / ๐Ÿ“บ / ๐ŸŒณ / ๐Ÿ“–
tags: biochem derm repeat

 Login (or register) to see more


 +2  upvote downvote
submitted by โˆ—okokok1(38)
get full access to all contentpick a username

Albinism: Normal melanocyte number with DECREASED melanin production due to decreased tyrosinase activity or defective tyrosine transport. risk of skin cancer.

get full access to all contentpick a username
okokok1  the choice "decreased number of epidermal melanocytes" is vitiligo. +7
fatboyslim  @okokok1 isn't vitiligo immune destruction of melanocytes (choice C)? Maybe it's both. Since if you destroy the melanocytes you will have fewer numbers of them in the epidermis? +

In the same vein, a darker-skinned person would have an increased number of melanosomes. BUT the SAME number of melanocytes and melanophages as a lighter-skinned person.



 +0  upvote downvote
submitted by โˆ—tamarafainblout(1)
get full access to all contentpick a username

why cant it be A? Aren't melanocytes derived from neural crest cells?

get full access to all contentpick a username



 -2  upvote downvote
submitted by โˆ—the_enigma28(69)
get full access to all contentpick a username

Child has albinism. Defective melanin synthesis due to deficiency of enzyme tyrosine hydroxylase. FA 2020, page 476

get full access to all contentpick a username
topgunber  tyrosinase. tyrosine hydroxylase would make L-dopa +2
sabrooza  It is Tyrosinase deficiency not (Tyrosinase hydroxylase ) +1



Must-See Comments from nbme16

bingcentipede on Cerebral edema
zincy7 on Gastrin
cassdawg on Kidney
medninja on Lysosomes
cassdawg on Sildenafil
cassdawg on Feces-contaminated soil
cassdawg on Presence of an internal ribosome entry site
cassdawg on Peutz-Jeghers
hungrybox on Induction of cytochrome P450 enzymes that ...
andro on Antagonizes VLDL-cholesterol secretion
bingcentipede on Decreased function of Na+โ€“K+ ATPase
bingcentipede on Glyceraldehyde-3-phosphate dehydrogenase
cassdawg on 46,XXY
bingcentipede on Grade 4/6, holosystolic murmur heard best ...

search for anything NEW!