The Usher syndrome type IC {USHIC} and familial hyperinsulinism [HI) loci have been assigned to chromosome Ilpl4-15.1, within the interval DIIS419-DI1SI310. We have constructed a yeast artificial chromosome {YAC} contig, extending from D11S926 to DIIS899, which encompasses the critical regions for both USHIC and HI and spans an estimated genetic distance of ---4 cM. A minimal set of six YAC clones constitute the contig, with another 22 YACs confirming the order of sequence-tagged sites [STSs) and position of YACs on the contig. A total of 40 STSs, including 10 new STSs generated from YAC insert-end sequences and inter-A/u PCR products, were used to order the clones within the contig. This physical map provides a resource for identification of gene transcripts associated with USHIC, HI, and other genetic disorders that map to the DllS?26-DIIS899 interval.