Genetic Abnormalities in Large to Giant Congenital Nevi: Beyond NRAS Mutations.
J Invest Dermatol
; 139(4): 900-908, 2019 04.
Article
in En
| MEDLINE
| ID: mdl-30359577
ABSTRACT
Large and giant congenital melanocytic nevi (CMN) are rare melanocytic lesions mostly caused by postzygotic NRAS alteration. Molecular characterization is usually focused on NRAS and BRAF genes in a unique biopsy sample of the CMN. However, large/giant CMN may exhibit phenotypic differences among distinct areas, and patients differ in features such as presence of multiple CMN or spilus-like lesions. Herein, we have characterized a series of 21 large/giant CMN including patients with spilus-type nevi (9/21 patients, 42.8%). Overall, 53 fresh frozen biopsy samples corresponding to 40 phenotypically characterized areas of large/giant CMNs and 13 satellite lesions were analyzed with a multigene panel and RNA sequencing. Mutational screening showed mutations in 76.2% (16/21) of large/giant CMNs. A NRAS mutation was found in 57.1% (12/21) of patients, and mutations in other genes such as BRAF, KRAS, APC, and MET were detected in 14.3% (3/21) of patients. RNA sequencing showed the fusion transcript ZEB2-ALK and SOX5-RAF1 in large/giant CMN from two patients without missense mutations. Both alterations were not detected in unaffected skin and were detected in different areas of affected skin. These findings suggest that large/giant CMN may result from distinct molecular events in addition to NRAS mutations, including point mutations and fusion transcripts.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Skin Neoplasms
/
DNA, Neoplasm
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GTP Phosphohydrolases
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Membrane Proteins
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Mutation
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Nevus, Pigmented
Type of study:
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Adolescent
/
Adult
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Child
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Child, preschool
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Female
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Humans
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Infant
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Male
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Middle aged
Language:
En
Journal:
J Invest Dermatol
Year:
2019
Document type:
Article
Affiliation country:
Spain