Multiple gastrointestinal stromal and other tumors caused by platelet-derived growth factor receptor alpha gene mutations: a case associated with a germline V561D defect.
BACKGROUND
Gastrointestinal stromal tumors (GISTs) may be caused by somatic or germline mutations of the KIT and PDGFRA genes, but most GISTs associated with neuroendocrine tumors (NETs) are not, suggesting that other molecular pathways are implicated in their pathogenesis.


OBJECTIVE
In the course of investigating NETs and GIST genetics, we encountered a patient who had a unique combination of multiple fibrous polyps and lipomas of the small intestine and several gastric GISTs.


METHODS
The study included the clinical description of a unique patient, DNA sequencing of germline and tumor DNA, and comparative genomic hybridization (CGH) and allelic marker analysis of tumor DNA.


RESULTS
The patient was found to carry a germline PDGFRA mutation (V561D) in the heterozygote state; it has only been seen rarely before and only in the somatic state in sporadic GISTs. CGH identified losses of chromosomal regions 1p33-36, 9q12-24, 11q13, and 16q; loss of the 14q region that is commonly lost in NETs and GISTs was shown by DNA marker analysis. These changes are likely to point to secondary and tertiary genetic hits involved in the formation of these rare tumors.


CONCLUSIONS
Multiple GISTs and other tumors may be caused by germline PDGFRA gene mutations; the V561D mutation can occur in the germline state and lead to a syndrome that should not be confused with other genetic conditions associated with a predisposition to NETs and other tumors. A number of chromosomal loci are likely to be involved in the PDGFRA V561D-dependent tumorigenesis, as shown by CGH and other DNA analyses.
Pasini
Barbara
B
Department of Genetics, Biology, and Biochemistry, University of Turin, Turin, Italy.
Matyakhina
Ludmila
L
Bei
Thalia
T
Muchow
Michael
M
Boikos
Sosipatros
S
Ferrando
Barbara
B
Carney
J Aidan
JA
Stratakis
Constantine A
CA
D001224:Aspartic Acid / Q000235:genetics; D001483:Base Sequence; D004252:DNA Mutational Analysis; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000235:genetics*; D018095:Germ-Line Mutation; D006801:Humans; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000235:genetics*; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics*; D014633:Valine / Q000235:genetics
D001224:Aspartic Acid; D020796:Receptor, Platelet-Derived Growth Factor alpha; D014633:Valine