Pharmacogenetics of schizophrenia in real clinical practice: a clinical case

Schizophrenia is a socially significant mental disorder characterized by early onset and high time and financial expenditure on treatment. The basic drugs in these patients are antipsychotics that are highly effective against the positive and negative symptoms of schizophrenia, but at the same time have a wide range of adverse reactions (ARs). The clinical effect and tolerability of antipsychotics are variable and depend on the characteristics of genetically determined mechanisms (transportation, biotransformation, and elimination).

The paper describes a clinical case of a female patient with schizophrenia who has been noted to be unresponsive to antipsychotic therapy for some years after the onset of the disease. After pharmacogenetic testing, she was found to be homozygous for the nonfunctional allelic variant CYP2D6*4 (1934 G>A, rs3892097), which was the reason for the complete shutdown of isoenzyme 2D6 activity and the development of ARs in the use of initial doses of antipsychotic drugs, as well as for an increase in the severity of ARs with aggravation of psycho-producing symptoms with an even slow titration of the daily dose.

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