Association between the catechol-o-methyltransferase val158met polymorphism with susceptibility and severity of carpal tunnel syndrome

The potential impact of COMT gene variants on dopamine regulation and phenotypic traits of ASD patients

Catechol-O-methyltransferase (COMT) enzyme has a major role in the adjustment of catechol-dependent functions, for example, cognition, cardiac function, and pain processing. The pathogenesis of autism may be related to dysfunction in the midbrain dopaminergic system. Therefore, we aimed to clarify how COMT gene variants affect dopamine level, and its potential impact on phenotype traits of autistic patients. 52 autistic patients were subjected to comprehensive clinical investigation, sequencing of exon 4 of the COMT gene by direct Sanger Sequencing, and measuring of dopamine levels. The clinical presentations of autistic subjects were correlated with detected COMT variants and dopamine level. Our molecular results revealed that three COMT variants were found: rs8192488 [C > T], rs4680 (Val158Met) and rs4818 [C > G]. Within autistic subjects, Val158Met rs4680 carriers were significantly distributed (71.2% P = 0.014) accompanied with abnormal dopamine, abnormal Electroencephalogram (EEG) and increasing the severity of autistic behaviour. As regards the haplotypes, CC/VM/CG block was significantly distributed among the autistic subjects (30.8%) presented with low mean dopamine level (15.8 ± 4.7 pg/ml, p = 0.05), while CC/MM/CC were presented with high mean level (77.8 ± 8.6 pg/ml, p = 0.05). Evidence is currently limited and preliminary, further studies are necessary in order to set up a coherent dopaminergic model of Autism Spectrum Disorder (ASD), which would further pave the way for an adequate treatment.

Analysis of the relationship between COMT polymorphisms and endometriosis susceptibility

This study was aimed to explore the correlation between catechol-O-methyltransferase (COMT) gene polymorphisms and endometriosis susceptibility in Chinese Han population.This case-control study recruited 134 endometriosis patients and 139 healthy individuals. COMT gene rs4680, rs2020917, and rs4646312 polymorphisms in the subjects were genotyped by the polymerase chain reaction-restriction fragment length polymorphism method. Association between COMT polymorphisms and endometriosis susceptibility was evaluated by χ test and adjusted by Logistic regression. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to present the relative risk of endometriosis.A allele of rs4680 was distinctly correlated with increased susceptibility of endometriosis (OR = 1.450, 95% CI = 1.012-2.076). However, when adjusted by the confounding factors, these associations become not significant. We failed to find any significant association between rs2020917 and endometriosis risk in the crude results. The adjusted results suggested that rs2020917 TT genotype and T allele were distinctly correlated with enhanced endometriosis risk (TT vs CC: P = .038, OR = 2.894, 95% CI = 1.060-7.903; T vs C: P = .039, OR = 1.481, 95% CI = 1.021-2.149). Besides, rs4646312 C allele was significantly correlated with endometriosis risk both in the crude (P = .027, OR = 1.502, 95% CI = 1.047-2.154) and adjusted (P = .019, OR = 1.564, 95% CI = 1.078-2.269) results.COMT polymorphisms might predict the occurrence of endometriosis.

Heterotrophic Ossification of the Flexor Retinaculum in a Patient with Ankylosing Spondylitis

Carpal tunnel syndrome (CTS) is the most common peripheral neuropathy. This syndrome has various etiologies of which heterotopic ossification of the flexor retinaculum is a rare cause. Ankylosing spondylitis (AS) is a systemic, progressive inflammatory disease of unknown etiology that mainly affects the axial skeleton and rarely causes peripheral neurological symptoms. A 48-year-old woman presented with numbness and pain in her right hand. Ten years earlier, she was diagnosed with AS. Electrodiagnostic evaluation revealed severe median nerve compression at the right wrist. The patient underwent surgery for severe CTS. During the operation, the flexor retinaculum could not be incised due to marked stiffness. Ossification of the flexor retinaculum was seen, and the retinaculum was partially excised with an osteotome and Kerrison rongeur. The patient's complaints resolved almost totally after the operation. AS is a common systemic inflammatory disease that can produce heterotopic ossification of the flexor retinaculum. Preoperative wrist computed tomography should be obtained in patients with CTS and AS.