Fibromyalgia (FM) is a disorder characterized by chronic musculoskeletal pain, fatigue, and cognitive problems. Neurotransmitters, mainly catecholamines, appear to be involved in regulating the etiology of FM. Catechol-O-methyltransferase (COMT) is involved in catabolizing catecholamines such as norepinephrine. The most common variant studied in the COMT gene is the valine (Val) to methionine (Met) substitution at codon 158. This is the first study in Sudan addressing FM cases and genetic susceptibility to the disease. We aimed in this study to investigate the frequency of COMT Val 158 Met polymorphism among patients with FM, rheumatoid arthritis, and in healthy individuals. Genomic DNA from forty female volunteers was analyzed: twenty were from primary and secondary FM patients, ten were from rheumatoid arthritis patients, and ten were from healthy control. FM patients’ age was ranging from 25 years to 55 with a mean of 41.14 ± 8.90. The mean age of the rheumatoid arthritis patients and healthy individuals was 31.3 ± 7.5 and 38.6 ± 11.2, respectively. Samples were genotyped for COMT single nucleotide polymorphism rs4680 (Val158Met), using the amplification-refractory mutation system (ARMS-PCR). Genotyping data have been analyzed using the Chi-square and Fisher exact test. The most common genotype among the study participants was the heterozygous Val/Met found in all participants. It was the only genotype found in the healthy participants. The genotype Met/Met was found only in FM patients. The genotype Val/Val was found only in rheumatoid patients. Analyses have shown no association between the Met/Met genotype and FM, and this could be due to a small sample size. In a larger sample size, a significant association could be found as this genotype was shown only by FM patients. Moreover, the Val/Val genotype, which is shown only among rheumatoid patients, might protect them from developing FM symptoms.

中文翻译：

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COMT Val158Met 多态性与苏丹喀土穆州纤维肌痛的关联

纤维肌痛 (FM) 是一种以慢性肌肉骨骼疼痛、疲劳和认知问题为特征的疾病。神经递质（主要是儿茶酚胺）似乎参与调节 FM 的病因。儿茶酚-O-甲基转移酶 ( COMT ) 参与去甲肾上腺素等儿茶酚胺的分解代谢。COMT基因中最常见的变异是密码子 158 处的缬氨酸 (Val) 替换为蛋氨酸 (Met)。这是苏丹第一项针对 FM 病例和对该疾病的遗传易感性的研究。我们本研究的目的是调查COMT的频率FM、类风湿性关节炎患者和健康个体中的 Val 158 Met 多态性。对 40 名女性志愿者的基因组 DNA 进行了分析：20 名来自原发性和继发性 FM 患者，10 名来自类风湿性关节炎患者，10 名来自健康对照。FM患者的年龄范围为25岁至55岁，平均为41.14±8.90。类风湿性关节炎患者和健康个体的平均年龄分别为31.3±7.5岁和38.6±11.2岁。对样本进行COMT基因分型单核苷酸多态性 rs4680 (Val158Met)，使用扩增-难治性突变系统 (ARMS-PCR)。使用卡方和费舍尔精确检验对基因分型数据进行了分析。研究参与者中最常见的基因型是所有参与者中发现的杂合 Val/Met 基因型。这是在健康参与者中发现的唯一基因型。Met/Met 基因型仅在 FM 患者中发现。Val/Val 基因型仅在类风湿患者中发现。分析显示 Met/Met 基因型与 FM 之间没有关联，这可能是由于样本量较小。在较大的样本量中，可以发现显着的关联，因为这种基因型仅在 FM 患者中表现出来。此外，仅在类风湿患者中出现的 Val/Val 基因型可能会保护他们免于出现 FM 症状。