At least three genes account for familial papillary thyroid carcinoma: TCOand MNG1 excluded as susceptibility loci from a large Tasmanian family

Recent studies have mapped two susceptibility loci which appear to account for familial multinodular goitre (MNG1) and a variant of familial papillary thyroid cancer (PTC), with associated multinodular goitre (TCO). A Tasmani an family (Tas1) has be en identified with an autosomal dominant form of FT C. This study has examined the MNG1 and TCO loci to determine if they are simi larly predisposing the Tas1 family to PTC. Linkage analysis using identical microsatellite markers described in the two previous studies was used to d etermine the significance of these loci in the Tasmanian family. The result ant LOD scores were sufficiently negative using multipoint parametric analy sis to exclude these two loci from involvement in the Tasmanian family In addition, six candidate genes, RET, TRK, MET, TSHR, APC and PTEN were al so excluded as susceptibility genes in Tas1 by using microsatellites that a re positioned in or in close proximity to these genes. These results sugges t that there are at least three susceptibility genes that predispose famili es to familial PTC.