Estimation of CYP3A4*1B single nucleotide polymorphism in patients with recurrent Major Depressive Disorder

Major depression is the most common mental illness in the world. Failures in treatment may occur due to the presence of a subtype of depression called TRD (Treatment- Resistant Depression). CYP3A4 polymorphism (rs2740574) can increase the activity of Cytochrome P450 3A4, contributing to faster metabolism of xenobiotics and reduced response to treatment. The aim of the study was to assess the distribution of CYP3A4*1B in study and control group and to estimate the influence of particular genotypes on parameters such as: age at onset, severity of symptoms before treatment and on the effectiveness of therapy.

Total of 192 patients were enrolled in this study (102 patients suffering from recurrent Major Depression Disorder, 90 healthy blood donors). PCR Restriction Fragment Length Polymorphism method with MboII enzyme was performed. The presence of CYP3A4*1B allele was evaluated on the basis of agarose gel electrophoresis.

There was a tendency in frequency of genotypes distribution in the study group in comparison with the control group (p = 0.050). There were no statistically significant differences in the distribution mutant allele among these two groups, but there was a tendency for mutant allele to occur more often in the study group (p = 0.050). No significant correlations were found between the specific genotype and the studied parameters: age at onset (p = 0.232), severity of the symptoms (p = 0.946), and efficacy of treatment (p = 0.882).

The study suggests that CYP3A4*1B polymorphism have no influence on the predisposition to depression, the severity of depressive symptoms and the efficiency of antidepressant therapy.