Interestingly, a clear association was found among our cases between mutation of the NF2 gene and monosomy 22, but not del(22q); in addition, all NF2-mutated cases corresponded to older menopausal women, supporting the notion that NF2-mutated patients could represent a well-defined and unique cytogenetic and clinical subtype of meningiomas in which acquisition of monosomy 22 could be sequentially followed by NF2 mutation during the development of the disease. The gene discussed is NF2; the disease is meningioma.