title: Evidence that a gene for essential tremor maps to chromosome 2p in four families.
abstract: In this Journal, we previously reported genetic linkage between loci on chromosome (chr)2p(ETM) and dominantly inherited essential tremor (ET) in a large American kindred of Czech ancestry. Other investigators reported another ET susceptibility locus on chr 3q (FET1) which accounted for over half of the Icelandic families that were studied. We now report evidence for linkage to the ETM locus in three additional, unrelated American families with ET and exclude the FET1 locus in these families. Fine mapping results, using an "affecteds-only" model in all four American families, demonstrate positive combined pairwise lod scores (Z) at the ETM locus with aZ(max) = 5.94 at a recombination fraction (theta) = 0.00 for locus D2S220. Haplotype reconstruction places the ETM gene in a 9.10 cM interval between the D2S224 and D2S405 loci. Multipoint linkage analysis suggests that the ETM gene is in the 2.18 cM interval between loci D2S2150 and D2S220 with a Z(max) = 8.12. These findings may facilitate the search for a gene that causes ET and may further our understanding of other disorders that are associated with tremor [corrected].
authors.affiliation: Laboratory of Clinical Neurogenetics, Wadsworth Center for Laboratories and Research New York State Department of Health, Albany 12201-0509, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Higgins
authors.forename: J M
authors.initials: JM
authors.lastname: Loveless
authors.forename: J
authors.initials: J
authors.lastname: Jankovic
authors.forename: P I
authors.initials: PI
authors.lastname: Patel
mesh_terms: D000328:Adult; D017668:Age of Onset; D002869:Chromosome Aberrations / Q000235:genetics*; D025063:Chromosome Disorders; D002889:Chromosomes, Human, Pair 2 / Q000235:genetics*; D005260:Female; D005799:Genes, Dominant; D008040:Genetic Linkage / Q000235:genetics; D005819:Genetic Markers; D005838:Genotype; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D008126:Lod Score; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D014202:Tremor / Q000175:diagnosis / Q000235:genetics*; D014481:United States
chemical_list: D005819:Genetic Markers