transcript map of a 900kb genomic region in xp221p222 identification of 12 novel genes the xp221p222 interval is a focus of interest as a number of hereditary disease loci have been mapped to this region including xlinked nonsyndromic sensorineural deafness dfn6 xlinked juvenile retinoschisis rs and several xlinked mental retardation syndromes in the course of cloning the rs gene we have assembled yac and pac contigs of the 900kb candidate region delimited by dxs418 and dxs999 in this study we now report the construction of a first transcript map of this chromosomal interval by combining exon trapping est mapping and computational gene identification methods overall this strategy has led to the assembly of at least 12 novel transcripts positioned within the dxs418dxs999 region one of these encoding a putative protein kinase motif with significant homology to the rat p58gta protein kinase domain and another a putative neuronal protein with strong homology to a drosophila transcriptional repressor