Essential tremor (ET), the most common movement disorder in humans, ap
pears to be inherited as an autosomal dominant trait in many families(
1,2). The familial form is called familial essential tremor (FET), whi
ch seems similar to sporadic essential tremor. ET is a cause of substa
ntial disability, particularly in the elderly(1). The prevalence of Pa
rkinson's disease and dystonia may be increased in families with ET, b
ut other movement disorders are seldom encountered in these families(3
,4). Here we report the results of a genome-wide scan for FET genes in
16 Icelandic families with 75 affected individuals, in whom FET was a
pparently inherited as a dominant trait. The scan, which was performed
with a 10-cM framework map, revealed one locus on chromosome 3q13 to
which FET mapped with a genome-wide significance when the data were an
alysed either parametrically, assuming an autosomal dominant model (Io
d score = 3.71), or non-parametrically (NPL Z score = 4.70. P < 6.4 x
10(6)).