Fluorescence in situ hybridization analysis of allelic losses involving the long arm of chromosome 17 in NF1-associated neurofibromas.
Neurofibromatosis type 1 (NF1) is a common autosomal dominant condition associated with germline mutations of the NF1 gene located at chromosome band 17q11.2. Molecular analysis of a number of NF1-specific tumors has shown the inactivation of both NF1 alleles during tumorigenesis, supporting the tumor suppressor hypothesis for the NF1 gene. Using interphase dual-color fluorescence in situ hybridization (FISH) technique on paraffin-embedded tissues, we studied 11 plexiform, 4 cutaneous, and 6 subcutaneous neurofibromas. Cytogenetic analysis was conducted using two probes, one specific for the NF1 region (RP11-229K15) and one for the centromeric region of chromosome 17 as control. No large somatic deletions were found. Only in one of the plexiform neurofibromas loss of a whole chromosome 17 was observed. If we assume that dual-color FISH analysis is sensitive enough to detect the majority of large somatic deletions present, then other mutational mechanisms affecting the NF1 gene are probably involved in neurofibroma formation, and other tumor suppressor genes may play an important role in NF1 tumorigenesis.
De Luca
Alessandro
A
IRCCS-CSS, San Giovanni Rotondo and CSS-Mendel Institute, Viale Regina Margherita 261, 00198 Rome, Italy. a.deluca@css-mendel.it
Bernardini
Laura
L
Ceccarini
Caterina
C
Sinibaldi
Lorenzo
L
Novelli
Antonio
A
Giustini
Sandra
S
Daniele
Innocenzi
I
Calvieri
Stefano
S
Mingarelli
Rita
R
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002874:Chromosome Mapping; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics*; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D009456:Neurofibromatosis 1 / Q000235:genetics*; D017384:Sequence Deletion