Familial partial lipodystrophic syndrome 3 (FPLD3) is associated with mutations in the transcription factor PPARγ. One of these mutations, the P467L, confers a dominant negative effect. We and others have previously investigated the pathophysiology associated to this mutation using a humanised mouse model that recapitulates most of the clinical symptoms observed in patients when phenotyped under different experimental conditions. One of the key clinical manifestations observed both, in humans and mouse models, is the ectopic accumulation of fat in the liver. Here, we dissect the molecular mechanisms that contribute to the excessive accumulation of lipids in the liver and characterise the negative effect of this PPARγ mutation on the activity of PPARα in vivo when activated by fibrates. P465L mice have increased levels of insulin and free fatty acids (FFA), exhibit decreased levels of Very Low Density Lipoproteins (VLDL) when fed high fat diet (HFD) and a partial impaired response to the hypolipidemic action of WY14643. This indicates that the deleterious effects of P465L-PPARγ mutation may be magnified by their collateral negative effect on PPARα function. This article is protected by copyright. All rights reserved.