Microsatellite markers D5S527, SPARC and D5S519, which previously mapped the TCOF1 gene within a 2.1-cM interval on chromosome 5 (5q32-33.1), were used to follow the transmission of the TCOF1 mutated locus.
Previous studies have shown that the Treacher Collins syndrome locus is flanked by D5S519 and SPARC, and a yeast artificial chromosome contig encompassing this "critical region" has been completed.
Previous studies have localized the TCOF1 locus between D5S519 (proximal) and SPARC (distal), a region of 22 centirays as estimated by radiation hybrid mapping.
This information combined with the data generated by genetic linkage analysis demonstrated that the TCOF1 locus is closely flanked proximally by IG90 and distally by SPARC.
The most likely location for the TCOF1 locus within this marker framework is in the D5S519-SPARC interval; a region estimated to be approximately 880 kb.