Background: Cholinergic muscarinic 2 receptor (CHRM2) is believed to be involved in neuronal excitability, synaptic
plasticity and feedback regulation of acetylcholine release. Polymorphism in the CHRM2 gene had been shown a significant
association with intelligence.
Objective: To investigate single nucleotide polymorphisms (SNPs) in CHRM2 gene with the learning aptitude among medical and fine arts students at Srinakharinwirot university, Thailand.
Material and Method: A total of two hundred blood samples were withdrawn from medical (100) and fine arts (100) students. DNAs were extracted using DNA extraction kit. SNP primers were designed and screened. Genotyping was performed by real-time PCR and high-resolution melting (HRM) analysis and confirmed by sequencing. The difference in genotypic
distribution was analyzed using Pearson’s Chi-square test implemented in SPSS program version 11.5. Significant level was set at p<0.05.
Results: Two SNPs in CHRM2 gene, rs2061174 and rs6948054, showed significant difference in genotype distribution between medical and fine arts students (p<0.05). The rs2061174 showed significant at p = 0.001, OR and 95% CI were 3.78
(2.00-7.14), whereas the rs6948054 was significant at p = 0.012, OR and 95% CI were 2.50 (1.32-4.77).
Conclusion: Two SNPs in CHRM2 gene, rs2061174 and rs6948054, may be used as biomarker to distinguish the learning aptitude among Thai individual.

Keywords: Cholinergic muscarinic 2 receptor, Polymorphisms, Biomarker, CHRM2 gene, SNPs