A PROVISIONAL TRANSCRIPT MAP OF THE SPINAL MUSCULAR-ATROPHY (SMA) CRITICAL REGION

YACs from the region containing the spinal muscular atrophy (SMA) locu s at 5q12 have been used as probes in a direct screening of cDNA libra ries to isolate 8 cDNAs, mapped to different YAC fragments. Three clon es showed complete identity to the genes for cyclin B1 (CCNB1), the p4 4 subunit of the transcription factor BTF2 (BTF2p44), and cofilin (CFL ). Two clones showed partial identity to the beta-gIucuronidase gene ( GLCB) and a rat integral membrane glycoprotein gene (RNINMEGLA). CFL t urned out to have been identified by a pseudogene sequence. Related se quences occurred on other chromosomes. CCNB1 and BTF2p44 were given an exact location. The GLCB-like gene and the RNINMEGLA-like gene detect ed loci on both 5q and 5p. The remaining three cDNA clones were locali zed to the SMA region only. Their sequences did not show identity to a ny gene for which a function is already known. Two of them have now tu rned out to be identical to recently reported candidate genes for SMA.