Article

The BTBD9 gene may be associated with antipsychotic-induced restless legs syndrome in schizophrenia

Department of Psychiatry, Gachon University, School of Medicine, Incheon, Korea.
Human Psychopharmacology Clinical and Experimental (Impact Factor: 1.85). 03/2013; 28(2). DOI: 10.1002/hup.2287
Source: PubMed

ABSTRACT OBJECTIVE: A genome-wide association study and several replication studies have shown significant association between BTBD9 gene single nucleotide polymorphisms and restless legs syndrome (RLS). The aim of this study is to investigate the association between the BTBD9 gene polymorphisms and antipsychotic-induced RLS in schizophrenic patients. METHODS: Restless legs syndrome symptoms were evaluated using the diagnostic criteria of the International Restless Legs Syndrome Study Group in 190 Korean schizophrenic patients. We genotyped the rs9357271 and rs3923809 polymorphisms of the BTBD9 gene in schizophrenic patients with (n = 96) and without (n = 94) RLS symptoms. RESULTS: There was a significant difference in the allele frequency (χ(2) = 8.14, p = 0.004) of the rs9357271 polymorphism between schizophrenic patients with and without RLS symptoms. Significant genotypic association of this single nucleotide polymorphisms with RLS symptoms was also observed for the dominant model (χ(2) = 10.32, p = 0.001) and heterozygous model (χ(2) = 10.9, p = 0.001). When we compared the frequencies of the rs3923809-rs9357271 haplotypes between the two groups, the overall haplotype frequencies were significantly different (permuted p = 0.037), and the A-T haplotype was significantly more frequent in the RLS symptom group than in the no RLS symptom group (0.112 vs. 0.041, permuted p = 0.007). CONCLUSIONS: These data suggest that the BTBD9 gene is associated with antipsychotic-induced RLS symptoms in schizophrenic patients. Copyright © 2013 John Wiley & Sons, Ltd.

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    • "Furthermore, one study found that loss of BTBD9 significantly disrupted sleep with concomitant increases in waking and motor activity in a Drosophila model [18]. Recently Kang et al. reported that the BTBD9 gene affected susceptibility to antipsychotic-induced RLS [19]. This result is consistent with our finding that patients with a family history of idiopathic RLS were susceptible to olanzapine-induced RLS. "
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