CLONING AND CHARACTERIZATION OF MN1, A GENE FROM CHROMOSOME 22Q11, WHICH IS DISRUPTED BY A BALANCED TRANSLOCATION IN A MENINGIOMA

We have isolated a gene, called MN1, which resides on chromosome 22 an d which was found to be disrupted by a balanced translocation (4;22) i n meningioma 32. The MN1 gene spans about 70 kb and consists of at lea st two large exons of approximately 4.7 kb and 2.8 kb, The MN1 cDNA co des for a protein of 1319 amino acids when the first methionine in the open reading frame is used. The MN1 cDNA contains two CAG repeats, on e of which codes for a string of 28 glutamines, The t(4;22) disrupts t he S-exon within the open reading frame, In meningioma 32 no expressio n of the MN1 mRNA is observed, These results suggest that inactivation of the MN1 gene in this tumour may contribute to its pathogenesis.