GABAA receptor- and GABA transporter polymorphisms and risk for essential tremor

Background: Clinical features and animal models of essential tremor (ET) suggest gamma-aminobutyric acid A receptor (GABA(A)R) subunits and GABA transporters as putative candidate genes. Methods: A total of 503 ET cases and 818 controls were investigated for an association between polymorphisms in 15 GABA(A)R and four GABA transporter genes and ET. Results: Nine nominally significant tagging SNPs (P values from 4.9 x 10(-2) to 5.2 x 10(-4)) were found in the hypothesis generation stage. Five SNPs were followed up in a second verification stage but failed to reach significance. (P values from 0.30 to 0.77). Discussion: In our samples, no evidence of association between GABAAR and GABA transporter genes with ET was detected. Further studies are necessary to clarify the role of these genes in ET.