Partial or total loss of chromosome 22 is often associated with tumors of the central nervous system and in particular with meningiomas. As in the case of other tumors, the ganglioside pattern is modified in transformed tissues. Cytogenetic analysis of 30 human meningiomas has been performed and the results compared to biochemical analysis of ganglioside distribution on the membrane surface. The meningiomas were divided into 2 groups on the basis of the presence or absence of chromosome 22. Thirteen tumors exhibited partial or total monosomy of the chromosome, whereas 17 were normal or showed other chromosomal anomalies. The GM, and GD, content of the meningiomas belonging to the 2 groups revealed a significant correlation between amount and reciprocal ratio of these 2 gangliosides and cytogenetic data. Tumors with monosomy 22 had a higher content of ganglioside GD, than samples without monosomy 22, where the main ganglioside was GM,. Other gangliosides such as GM,, GD,,, GD,, and GT were present in various amounts in the 2 groups. Considering the biosynthetic pathway of gangliosides, we hypothesize the involvement of a gene located on chromosome 22 in the regulation of the enzymes which catalyze either GD, synthesis (sialyltransferase 2, SAT-2) or its degradation to GM, (neuraminidase).