Ja. Biegel et E. Wentz, NO PREFERENTIAL PARENT OF ORIGIN FOR THE ISOCHROMOSOME 17Q IN CHILDHOOD PRIMITIVE NEUROECTODERMAL TUMOR (MEDULLOBLASTOMA), Genes, chromosomes & cancer, 18(2), 1997, pp. 143-146
We have shown that an i(17q) is the most frequent abnormality in centr
al nervous system primitive neuroectodermal tumors (PNETs; medulloblas
toma), implicating the presence of a tumor suppressor gene which maps
to 17p. In the present study, we investigated whether the deletion of
chromosome arm 17p that results from the formation of the i(17q) is pr
eferentially of maternal or paternal origin. Eight cases of primary PN
ETs of the posterior fossa were examined at five polymorphic loci whic
h map to 17p13. Two or three informative loci were detected in each fa
mily. Of the eight cases, four tumors evidenced loss of the paternal a
llele for loci on 17p13 and four tumors demonstrated maternal deletion
s. Although the number of cases is relatively small, these studies do
not implicate the loss of an imprinted gene as a mechanism for tumorig
enesis in children with central nervous system PNETs/medulloblastoma.
(C) 1997 Wiley-Liss, Inc.