Russell-Silver syndrome (RSS) is a heterogeneous disorder characterized mainly by pre- and postnatal growth retardation and characteristic dysmorphic features. The genetic cause of this syndrome is unknown. However, two autosomal translocations involving chromosome 17q25 were reported in association with RSS. Molecular analysis of the breakpoint on chromosome 17 of the de novo translocation previously described as t(1;17)(q31;q25) enabled us to refine the localization of the chromosome 17 breakpoint to 17q23-q24. Since no detailed mapping data were available for this region, we established a contig of yeast artificial chromosomes, P1 artificial chromosomes, bacterial artificial chromosomes, and cosmid clones for a 17q segment flanked by the sequence-tagged site (STS) markers D17S1557 and D17S940. This contig covers a physical distance of 4-5 Mb encompassing several novel markers. A transcript map was constructed by assigning genes and expressed sequence tags to the clone contig, and altogether 74 STS markers were mapped. Furthermore, the locus order and content provide insight into several duplication events that have occurred in the chromosomal region 17q23-q24. On the basis of our refined map, we have reduced the translocation breakpoint region to 65 kb between the newly derived markers 58T7 and CF20b. These data provide the molecular tools for the final identification of the RSS gene in 17q23-q24.
Copyright 2001 Academic Press.