The microtubule associated protein tau H1 haplotype and risk of essential tremor

Background and purpose Two recent studies investigated the association of the microtubule associated protein tau (MAPT) H1 haplotype, a known risk factor for neurodegenerative disease including progressive supranuclear palsy and Parkinson's disease (PD), with essential tremor (ET). Methods To confirm this association in a different population the distribution of allele and genotype frequencies for the MAPT H1/H2 tagging single-nucleotide polymorphism (SNP) rs1052553 in ET cases and controls enrolled in a clinical-epidemiological study of ET at Columbia University was analyzed. Results Overall, no association was observed between ET and the MAPT H1 haplotype. The analysis was also restricted to clinical subtypes including early-onset (40years of age), Ashkenazi Jewish ancestry, white non-Ashkenazi, or ET cases with a definite' or probable/possible' diagnosis; none of these stratified analyses showed evidence of association with ET. A meta-analysis of the H1/H2 tagging SNP rs1052553 in published data sets and the H1 haplotype with risk for ET in the current study was also performed and did not find evidence for association. Conclusions The inconsistent reports of association of MAPT H1 in three emerging studies (our own and two published studies) may reflect sampling issues and/or clinical heterogeneity in these populations.