Fat mass- and obesity-associated (FTO) gene and antipsychotic-induced weight gain: an association study.

OBJECTIVES

Genetic variation in the fat mass- and obesity-associated gene (FTO) has been associated with obesity in the general population. In this study we have investigated these variants for association with antipsychotic-induced weight gain (AIWG).

METHODS

A total of 218 patients with chronic schizophrenia or schizoaffective disorder treated mostly with clozapine or olanzapine for up to 14 weeks were included in the study. We analyzed 4 polymorphisms in intron 1 of the FTO gene (rs1421085, rs8050136, rs9939609, rs9930506) for association with AIWG using ANCOVA.

RESULTS

No statistically significant associations were observed between the single nucleotide polymorphisms and AIWG. However, patients homozygous for the A-allele of rs9939609 gained numerically higher weight than the other genotypic groups (AA: 5.26 ± 6.7%; TA: 4.66 ± 5.6%; TT: 4.21 ± 5.3%).

CONCLUSION

Our current observations suggest that the FTO gene variants investigated may not play a major role in AIWG.