ABSTRACT
BACKGROUND: Multiple meningiomas occur in <10% of meningioma patients. Their development may be caused by the presence of a predisposing germline mutation in the neurofibromatosis type 2 (NF2) gene. The predisposing gene in patients with non-NF2 associated multiple meningiomas remains to be identified. Recently, SMARCB1 was reported to be a potential predisposing gene for multiple meningiomas in a family with schwannomatosis and multiple meningiomas. However, involvement of this gene in the development of the meningiomas was not demonstrated. RESULTS: Five affected members of a large family with multiple meningiomas were investigated for the presence of mutations in SMARCB1 and NF2. A missense mutation was identified in exon 2 of SMARCB1 as the causative germline mutation predisposing to multiple meningiomas; furthermore, it was demonstrated that, in accordance with the two-hit hypothesis for tumourigenesis, the mutant allele was retained and the wild-type allele lost in all four investigated meningiomas. In addition, independent somatically acquired NF2 mutations were identified in two meningiomas of one patient with concomitant losses of the wild-type NF2 allele. CONCLUSION: It is concluded that, analogous to the genetic events in a subset of schwannomatosis associated schwannomas, a four-hit mechanism of tumour suppressor gene inactivation, involving SMARCB1 and NF2, might be operative in familial multiple meningiomas associated meningiomas.
Subject(s)
Chromosomal Proteins, Non-Histone/genetics , DNA-Binding Proteins/genetics , Genes, Neurofibromatosis 2 , Germ-Line Mutation/genetics , Meningioma/genetics , Transcription Factors/genetics , Base Sequence , DNA Mutational Analysis , DNA Primers/genetics , Female , Genotype , Humans , Male , Meningioma/pathology , Microsatellite Repeats/genetics , Molecular Sequence Data , Mutation, Missense/genetics , Pedigree , SMARCB1 ProteinABSTRACT
BACKGROUND: Women with a germline BRCA1 or BRCA2 mutation have a significantly increased risk of developing ovarian cancer compared with women in the general population and may consider bilateral prophylactic oophorectomy as a risk-reducing option. CASE: We report a case of occult fallopian tube cancer diagnosed at prophylactic surgery in a patient with a BRCA2 mutation. CONCLUSIONS: This report acts as a reminder of the importance of removing as much of the fallopian tube as possible during prophylactic surgery in BRCA1 and BRCA2 carriers and of the need for careful pathological examination of surgical specimens after surgery.
