Abstract The urofacial (Ochoa) syndrome (UFS) characterized by congenital obstructive uropathy and abnormal facial expression is a rare disorder caused by a single recessive disease gene. Our previous studies using homozygosity mapping have located the UFS gene to a genomic interval of approximately 360 kb on chromosome 10q23‐10q24. In this study, we have constructed a genomic sequence map covering the entire UFS interval and narrowed the disease interval to a genomic region of 220 kb that harbor the newly identified ACDP1 gene in addition to part of the GOT1 gene which has already been excluded as a candidate for UFS. Extensive search for mutations in the coding region, the 5′ and 3′ untranslated regions, the promoter region, and the exon/intron junctions failed to identify a pathogenic mutation in UFS patients. Furthermore, our analyses indicated that the same gene on chromosome 10q is responsible for all UFS patients from multiple ethnic groups. © 2003 Wiley‐Liss, Inc.