The purpose of this study was to explore the association of genetic polymorphism of genes related to pharmacokinetics or pharmacodynamics with
insulin resistance in children and adolescents with
autism spectrum disorder (ASD) and treated with
risperidone. All 89 subjects underwent measurement of fasting
blood glucose and
insulin levels,
body-weight and height. Genotyping was performed by TaqMan real-time polymerase chain reaction (PCR) (pharmacokinetics genes:
cytochrome P450 2D6 (
CYP2D6) *4 (rs3892097), *5 (gene deletion), *10 (rs1065852) and *41 (rs28371725),
ATP-binding cassette transporter B1 (ABCB1) 2677 G>T/A (rs2032582) and 3435C>T (rs1045642) and pharmacodynamics genes:
dopamine receptor D2 (DRD2) Tag-SNP (C>T) (rs4436578), DRD2 Tag1A (C>T) (rs1800497),
leptin gene (LEP) -2548G>A (rs7799039),
ghrelin gene (GHRL) -604G>A (rs27647) and
brain-derived neurotrophic factor (
BDNF) 196G>A (rs6265)). Drug levels were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results revealed that 5 (5.62%) patients presented with hyperglycaemia.
Insulin resistance was detected in 15 (16.85%) patients.
Insulin resistance was associated with LEP 2548 G>A and
BDNF 196 G>A polymorphism (p = 0.051 and p = 0.03). There was no association of pharmacokinetic gene polymorphisms (
CYP2D6 and ABCB1) and
risperidone levels with
insulin resistance. Multiple regression analysis indicated that
BDNF 196 G>A polymorphism was significantly associated with
insulin resistance (p = 0.025). This finding suggested that
BDNF 196 G>A polymorphism may be a
genetic marker for predicting
insulin resistance before initiating treatment in patients treated with
risperidone. Because of the small sample size, further studies are needed to confirm these results.