CLONING OF A NOVEL, ANONYMOUS GENE FROM A MEGABASE-RANGE YAC AND COSMID CONTIG IN THE NEUROFIBROMATOSIS TYPE-2 MENINGIOMA REGION ON HUMAN CHROMOSOME-22Q12

In order to permit detailed characterization of meningioma cases showi ng deletions within chromosomal band 22q12 and further systematically clone genes located within this region, we established a genomic YAC a nd cosmid contig which encompasses a region in excess of 1000 kb of 22 q12. The YAC contig consists of 6 YAC clones arranged into 5 overlappi ng steps covering more than 1100 kb. Two corresponding cosmid contigs consisting of 40 steps of overlapping groups of cosmids encompasses 90 0 - 1000 kb. This set of genomic clones provides a detailed physical m ap of this part of chromosome 22 and constitutes a basis for the isola tion and characterization of genes that may be located within this chr omosomal region. Employing the exon-amplification method on two cosmid s from the contig, we cloned a novel, anonymous gene, pK1.3, which pot entially encodes a protein of 683 amino acids with a predicted molecul ar weight of of 78.5 kD. Its 2.7 kb mRNA is expressed ubiquitously. We estimated the genomic size of this gene to 100 - 150 kb, and it is lo cated in the immediate centromeric vicinity of the neurofibromatosis 2 (NF2) tumor suppressor gene.