Genetic variants in melatonin synthesis and signaling pathway are not associated with adolescent idiopathic scoliosis.

Study Design. Genetic association study investigating the association of genetic markers of melatonin signaling and biosynthesis with adolescent idiopathic scoliosis (AIS). Objective. To determine whether gene polymorphisms related to the melatonin signaling or biosynthesis pathways are associated with AIS. Summary of Background Data. Data have been published on the potential role of gene polymorphisms for melatonin receptor (MTNR) 1B in predicting AIS. Other genes in the melatonin pathways have been tested for association with AIS. Methods. The following genes involved in melatonin synthesis were evaluated herein: tryptophan 5-hyroxylase 1 (TPH1), serotonin N-acetyltransferase (SNAT), and hydroxyindoleo-methyltransferase (HIOMT). In addition, proteins involved in melatonin signaling were also included in this study: MTNR1A, MTNR1B, and protein kinase C delta (PKC delta). High throughput microarray-based single nucleotide polymorphism (SNP) genotyping was performed for these seven genes using DNA samples from 589 AIS subjects and 1533 ethnically matched controls. Chi-square analyses of allele frequency between AIS cases and controls were performed and odds ratios were calculated for all SNP markers. Results. Three SNPs were tested for both MTNR1A and HIOMT, 4 for TPH1 and SNAT, 12 for PKC delta, and 7 for MTNR1B. The minor allele frequencies were not significantly different between AIS cases and controls. No association was thus found between AIS and the investigated SNPs. Conclusions. Genetic polymorphisms associated with either melatonin synthesis or its signaling pathway are unlikely to be commonly associated with AIS.