In:
Brain Pathology, Wiley, Vol. 25, No. 2 ( 2015-03), p. 182-192
Abstract:
The majority of pediatric low‐grade gliomas ( LGGs ) are characterized by constitutive activation of the mitogen‐activated protein kinase ( MAPK ) pathway through various mechanisms including BRAF mutations, inactivation of NF 1 , and KIAA 1549‐ BRAF and FAM 131 B ‐ BRAF fusions. The KIAA 1549‐ BRAF fusion typically results from a 2.0 Mb tandem duplication in chromosome band 7 q 34. In the present study, single nucleotide polymorphism ( SNP )‐based array analysis of three LGGs demonstrated deletions in 7 q 34 that resulted in a BRAF fusion. Case 1 was likely a pilocytic astrocytoma ( PA ) with three deletions in 7 q 33 q 34 and an exon 15‐9 KIAA 1549‐ BRAF fusion. SNP array analysis of case 2, a possible dysembryoplastic neuroepithelial tumor ( DNT ), revealed a 2.6 Mb deletion, which included the 5′ end of BRAF and extended to the 3′ end of FAM 131 B . In case 3, deletions involving BRAF and FAM 131 B were observed in both a primary and a recurrent PA . RNA ‐based sequence analysis of cases 2 and 3 confirmed a fusion between FAM 131 B exon 2 and BRAF exon 9. The presence of fusion transcripts in these three LGGs highlights the utility of SNP array analysis to identify deletions that are suggestive of fusion proteins. BRAF fusions can result from multiple non‐overlapping deletions, suggesting various complex mechanisms of formation.
Type of Medium:
Online Resource
ISSN:
1015-6305
,
1750-3639
DOI:
10.1111/bpa.2015.25.issue-2
Language:
English
Publisher:
Wiley
Publication Date:
2015
detail.hit.zdb_id:
2029927-8
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