Somatic instability of the NF2 gene in schwannomatosis.
BACKGROUND
Schwannomatosis is a newly described form of neurofibromatosis of unclear pathogenesis.


METHODS
We studied the NF2 locus on chromosome 22 in 7 tumor specimens resected from a 36-year-old man with schwannomatosis of the right ulnar nerve.


RESULTS
Unrelated truncating NF2 gene mutations were detected in 4 tumor specimens. None of the NF2 mutations were present in the blood specimen. Loss of heterozygosity at the NF2 locus was seen in all tumors, and in every case the same allele was lost. Loss of distal chromosome 22 markers was variable. Fluorescence in situ hybridization results were consistent with monosomy 22 in 4 tumors and mitotic recombination or nondisjunction in 1.


CONCLUSIONS
Molecular analysis of tumor specimens distinguishes schwannomatosis from other forms of neurofibromatosis. Further work is needed to understand the natural history and molecular biology of this condition.
Kaufman
David L
DL
Department of Plastic Surgery, Stanford University, CA, USA.
Heinrich
Bianca S
BS
Willett
Christine
C
Perry
Arie
A
Finseth
Frederick
F
Sobel
Raymond A
RA
MacCollin
Mia
M
D000328:Adult; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D004252:DNA Mutational Analysis; D016515:Genes, Neurofibromatosis 2 / Q000502:physiology*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D019656:Loss of Heterozygosity / Q000235:genetics; D008297:Male; D009442:Neurilemmoma / Q000235:genetics* / Q000473:pathology*; D010524:Peripheral Nervous System Neoplasms / Q000235:genetics* / Q000473:pathology*; D017354:Point Mutation / Q000235:genetics; D011110:Polymorphism, Genetic / Q000235:genetics; D014459:Ulnar Nerve / Q000473:pathology*