HOMOZYGOUS MUTATION AT CYTOCHROME P4502D6 IN AN INDIVIDUAL WITH SCHIZOPHRENIA - IMPLICATIONS FOR ANTIPSYCHOTIC-DRUGS, SIDE-EFFECTS AND COMPLIANCE

We report the case of a patient with schizophrenia who has suffered se vere side effects with many different antipsychotics. She is poorly co mpliant with treatment probably because of her experiences with medica tion. We determined her genotype at the CYP2D6 gene that codes for an enzyme principally involved in the metabolism of many antipsychotics. She was homozygous for the 'B' mutation, the most frequent of several known mutations. She therefore has no functioning CYP2D6 enzyme in com mon with 5%-10% of the population. This may explain why she is sensiti ve to quite moderate doses of antipsychotic medication, and more ratio nal prescribing may lead to fewer side effects and increased complianc e.