Localization of the 8q22.3 breakpoint (A) and the 14q13 translocation breakpoint (B) by FISH analysis. YACs spanning chromosome regions 8q22.3 (A) and 14q13 (B) were identified by searching the Whitehead Institute/MIT Center for Genome Research YAC database, and purchased from Research Genetics. The “+” symbol indicates that positive FISH signals were obtained on the corresponding derivative chromosome for a specific YAC, and “–” indicates absence of FISH signals on the corresponding derivative chromosome. The 8q22.3 breakpoint is defined within a <5-cM region flanked by markers AFMA082TG9 and GATA25E10, and the 14q13 breakpoint is between STSs WI-6583 and D14S989, <1 cM. ANGPT1, the angiopoietin-1 gene.