The breakpoint on 7p in a patient with t(6;7) and craniosynostosis is spanned by a YAC clone containing the D7S503 locus.

We previously reported a patient with an apparently balanced t(6;7) translocation and craniosynostosis. We now demonstrate, by fluorescence in situ hybridization, that the yeast artificial chromosome clone 933-e-1 from the Centre d'Etude du Polymorphisme Humain library harbouring the D7S503 locus spans the breakpoint on distal 7p. Recent reports have defined a candidate region for a Saethre-Chotzen craniosynostosis locus between the loci D7S513 and D7S516, a region that includes the D7S503 locus. Since the translocation carrier shows only some of the symptoms characteristic for the Saethre-Chotzen syndrome, it remains unresolved whether the gene disrupted by the translocation event is the only one causing craniosynostosis in this chromosomal region.