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Updated: Aug 18, 2026

Handwriting Analysis Indicates Spontaneous Dyskinesias in Neuroleptic Naïve Adolescents at High Risk for Psychosis
Published on: November 21, 2013
Cytochrome P450 2D6 genotyping and association with tardive dyskinesia in Chinese schizophrenic patients
L C Lam1, M M Garcia-Barcelo, G S Ungvari
1Department of Psychiatry, the Chinese University of Hong Kong, Kwai Chung Hospital, Hong Kong. cwlam@cuhk.edu.hk
Background:
The discovery of Cytochrome P450 2D6 (CYP 2D6) polymorphism is implicated in individual differences in drug metabolism rate. Mutation with defective alleles is associated with reduced metabolism of many anti-psychotic drugs metabolized by CYP 2D6. This may contribute to the development of tardive dyskinesia (TD) in patients with prolonged exposure to anti-psychotic drugs.
Methods:
In this controlled study, the genotype of CYP 2D6*10 alleles, movement disorders and clinical characteristics in 38 Chinese schizophrenic patients with TD were compared with 38 age- and sex-matched schizophrenia patients without TD.
Results:
There was no significant correlation between CYP 2D6*10 genotypes and TD in men. However, a significant increase in the frequency of CYP 2D6*10 allele was found in female patients with TD.
Conclusions:
The sex differences in CYP 2D6 genotyping and vulnerability to develop TD suggest that a biological predisposition that affects pharmacokinetics may be more significant in women, whereas other factors may be more important in men.

