Notable Genes Flashcards
1
Q
CDKN2A
A
Protein products p14ARF and p16 modulate cell cycle progression via p53 and retinoblastoma (Rb) pathways, respectively
- Familial melanoma (10%-60%)
- Spitz nevi (Homozygous loss of 9p21 (most predictive gene locus; corresponds to p16/CDKN2a gene) → ↑risk of metastasis and death)
- Familial Atypical Multiple Mole and Melanoma Syndrome (FAMMM):
- AD
- Multiple melanocytic nevi (50+)
- Family history of melanoma
2
Q
BRAF
A
- Melanoma: non-chronic sun-damage skin (V600E mutation most common), superficial spreading type
- Common nevus: 80% (>NRAS)
- Congenital nevus: low (
- Cardio-facial-cutaneous (CFC) syndrome: Coarse facies (long and broad), generalized ichthyosislike scaling, keratosis pilaris, CALMs, nevi, and sparse curly hair
- LEOPARD (10%): usually PTPN11 mutation, Lentigines (upper half of body; appear in childhood), CALMs, ocular hypertelorism (widely spaced eyes), low-set ears
- Langerhan cell histiocytosis (60%): V600E, a/w poor prognosis
- BAPoma: epithelioid spitzoid nevi (“BAPomas;” benign, possess concomitant activating BRAF > NRAS mutations)
BRAF inhibitors: vemurafenib, dabrafenib
3
Q
NRAS
A
- Melanoma: chronic sun-damaged skin, nodular melanoma
- Congenital nevi: majority
4
Q
c-KIT
A
- Melanoma: chronic sun-damage skin, acral, mucosal
- Leukemia cutis
- Piebaldism: c-kit activation is needed for melanocyte development/migration; piebaldism occurs as a result of c-kit loss ➔ impaired melanocyte migration and proliferation
- Imatinib
Mast cells, dendritic cells are c-KIT+ (CD117)
5
Q
GNAQ/GNA11
A
- Melanoma: uveal melanoma (high risk of metastasis especially if also has BAP1 loss)
- Blue nevi: activating mutation seen in 80% blue nevi, malignant blue nevus driver (especially if also has BAP1 loss). Note that DPNs do NOT have GNAQ mutations.
- Nevus of ota
- Port-wine stain
- Sturge-Weber
6
Q
HRAS
A
- Spitz
- Nevus spilus
- Phakomatosis pigmentokeratotica
- nevus sebaceous
7
Q
BAP1
A
