NBME 16 Inability to produce melanin (NBME Answers)

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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 🔍 / 📺 / 🌳 / 📖
tags: biochem derm repeat

+2 upvote downvote
submitted by ∗okokok1(38)

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

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.

+/- namesthegame22(13)

+0 upvote downvote
submitted by ∗tamarafainblout(1)

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

-2 upvote downvote
submitted by ∗the_enigma28(69)

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

topgunber tyrosinase. tyrosine hydroxylase would make L-dopa +2

sabrooza It is Tyrosinase deficiency not (Tyrosinase hydroxylase ) +1

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