Apparent genetic homogeneity of the treacher Collins-Franceschetti syndrome

The Treacher Collins-Franceschetti syndrome (TCOF) or mandibulofacial dysostosis (MFD) is an autosomal dominant disorder characterized by craniofacial abnormalities and hearing loss. A refined genetic linkage map of the TCOF locus was established in 8 independent families, using 12 microsatellite DNA markers of the distal 5q. Positive lod score values were obtained for all markers with a maximum at the D5S413 locus (Zmax = 3.79 at θ = 0%). Multipoint linkage analysis and haplotype analysis supported the location of the gene between loci D5S434 and D5S412. These results are consistent with previous linkage analysis [Dixon et al.: Am J Hum Genet 49:17–22, 1991, Am J Hum Genet 52:907–914, 1993; Jabs et al.: Genomics 11:193–198, 1991, Genomics 18:7–13, 1993] and provide further evidence of genetic homogeneity in this syndrome. © 1994 Wiley-Liss, Inc.