TOR1A sequence variants and the association with early-onset primary dystonia in the Chinese Han population

The Role of TOR1A Polymorphisms in Dystonia: A Systematic Review and Meta-Analysis

“…One additional study was extracted from the references of the identified studies and was included in the meta-analysis [30]. However, one study was excluded from further analysis, as it did not report genotype frequencies [31] and therefore 16 studies were finally included in the quantitative meta-analysis [14, 16, 20, 23, 24, 30, 32–41], involving in total 3103 dystonia cases and 3628 healthy controls. In total 9 TOR1A SNPs have been investigated so far (rs1801968 and rs2296793 in ten studies, rs1182 and rs3842225 in nine, rs13283584, rs11787741 and rs13297609 in two and rs2287367 and rs1043186 in one study).…”

“…One study revealed an association of a haplotype (constructed from rs2296793, rs1182 and rs3842225) with sporadic dystonia [36] while another one revealed a strong association of rs13283584 with idiopathic dystonia [38]. Association of rs1801968 with primary dystonia was reported in three studies [33, 39, 41] while another one revealed significant association only in cases with positive family history [32]. Association or a tendency for association of rs1182 was reported in three studies [37, 38, 40].…”

“…The majority of the studies were conducted in Chinese (n = 5) [20, 23, 34, 35, 41] and German (n = 4) [16, 30, 32, 38] populations. 10 studies reported inclusion of patients with positive family history of dystonia [20, 24, 32–35, 38–41] dystonia and in one study [41] was reported inclusion of participants positive for the ΔGAG TOR1A mutation.…”

“…10 studies reported inclusion of patients with positive family history of dystonia [20, 24, 32–35, 38–41] dystonia and in one study [41] was reported inclusion of participants positive for the ΔGAG TOR1A mutation. The characteristics of the included studies are summarized in S1 Table .…”

“…On the contrary, 216D allele in cis together with ΔGAG, may predispose for developing dystonia [46, 47]. Cheng et al reported that 216D allele was more abundant in patients with early-onset primary dystonia, while 216H allele was more frequent in the control group [41]. Furthermore, they observed that all the ΔGAG carriers, who also carried the 216D allele, were dystonic [41].…”