On this Mnemonic Monday, we challenge you to remember genes associated with Oculocutaneous Albinism. The genes associated with each type are listed.
Try, Try, 2-P, and TRiP, on a SLiC MAT
Tyrosinase (Type 1A OCA)
Tyrosinase (Type 1B OCA)
OCA2 (previously P-gene) (Type 2 OCA)
TRP-1 (Type 3 OCA)
SLC45A2 (also called MATP) (Type 4 OCA)
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Need a refresher on disorders with hypopigmentation and albinism? Check out page 220 of your 2020 Derm In-Review Study Guide.
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Check out the following article published in the Journal of Drugs in Dermatology (JDD) referencing today’s topic:
DeoxyArbutin and Its Derivatives Inhibit Tyrosinase Activity and Melanin Synthesis Without Inducing Reactive Oxygen Species or Apoptosis
Safety is a major concern in developing commercial skin-lightening agents. Here, we report the modulating effects of deoxyArbutin (dA) and its second-generation derivatives—deoxyFuran (dF), 2-fluorodeoxyArbutin (fdA), and thiodeoxyArbutin (tdA)—on tyrosinase, and consequently, on melanization. Results demonstrate that dA and its derivatives inhibit tyrosine hydroxylase and dopa oxidase activity of tyrosinase. The inhibition is dose-dependent, thereby inhibiting melanin synthesis in intact melanocytes, when used at concentrations that retain 95% viability of the treated cells in culture. Herein we demonstrate that dA, and its second-generation derivatives dF, fdA, and tdA, exhibit dose-dependent reductions in melanocyte cell number, primarily due to inhibition of proliferation rather than initiation of apoptosis as exemplified by hydroquinone (HQ), ie, cytostatic as opposed to cytotoxic. Human and murine melanocytes with functional mutations in either tyrosinase or tyrosinase-related protein 1 (Tyrp1) are less sensitive to the cytostatic effects of dA and its derivatives. Minimal amounts of reactive oxygen species (ROS) were generated upon treatment with dA and its derivatives, in contrast to a dramatic amount of ROS induced by HQ. This increase in ROS subsequently induced the expression of the endogenous antioxidant catalase in treated melanocytes. Treatment with exogenous antioxidants provided protection for melanocytes treated with HQ, but not dA and its derivatives, suggesting that HQ exerts more oxidative stress. These studies demonstrate that dA and its derivatives are relatively safe tyrosinase inhibitors for skin lightening or for ameliorating hyperpigmented lesions.
J Drugs Dermatol. 2012;11(10):e28-e34.
Read the full article here.
Test your knowledge!
Tyrosinase positive albinism (oculocutaneous albinism type 2) is caused by a mutation in which of the following:
B: P gene
C: Tyrosinase related protein 1
To find out the correct answer and read the explanation, click here.
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