Temporal lobe pleomorphic xanthoastrocytoma and acquired BRAF mutation in an adolescent with the constitutional 22q11.2 deletion syndrome.
DiGeorge syndrome, or velocardiofacial syndrome (DGS/VCFS), is a rare and usually sporadic congenital genetic disorder resulting from a constitutional microdeletion at chromosome 22q11.2. While rare cases of malignancy have been described, likely due to underlying immunodeficiency, central nervous system tumors have not yet been reported. We describe an adolescent boy with DGS/VCFS who developed a temporal lobe pleomorphic xanthoastrocytoma. High-resolution single nucleotide polymorphism array studies of the tumor confirmed a constitutional 22q11.21 deletion, and revealed acquired gains, losses and copy number neutral loss of heterozygosity of several chromosomal regions, including a homozygous deletion of the CDKN2A/B locus. The tumor also demonstrated a common V600E mutation in the BRAF oncogene. This is the first reported case of a patient with DiGeorge syndrome developing a CNS tumor of any histology and expands our knowledge about low-grade CNS tumor molecular genetics.
Murray
Jeffrey C
JC
Neurosciences Program, Hematology and Oncology Center, Cook Children's Medical Center, 901 Seventh Avenue, Suite 220, Fort Worth, TX 76104, USA. jmurray@cookchildrens.org
Donahue
David J
DJ
Malik
Saleem I
SI
Dzurik
Yvette B
YB
Braly
Emily Z
EZ
Dougherty
Margaret J
MJ
Eaton
Katherine W
KW
Biegel
Jaclyn A
JA
D000293:Adolescent; D001254:Astrocytoma / Q000235:genetics*; D002869:Chromosome Aberrations; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009154:Mutation / Q000235:genetics*; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*
C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf