Structure and partial genomic sequence of the human retinoblastoma susceptibility gene.

This report describes the genomic organization of the human retinoblastoma susceptibility locus. This gene spans approximately 200 kb of DNA within human chromosome 13, band q14. The previously determined cDNA sequence comprises 27 exons, ranging in size from 31 bp to 1873 bp, and 26 introns, ranging in size from 80 bp to 70,500 bp. We have mapped the positions of the exons and the positions of the recognition sites for six restriction endonucleases. We also present the sequence of 9.2% of the locus (18,335 bp), including approximately 200 bp of intron sequence immediately flanking each exon. This map of a wild-type allele will form the foundation for future studies of mutant, oncogenic alleles at this locus.