In this study, we utilize a lipidomics approach with functional analyses of patient-derived fibroblasts to examine genetic heterogeneity and its correlation to phenotype in TFP/LCHAD deficiency and additionally investigate liver mitochondria CL profile of a TFP-deficient mouse model. The gene discussed is TRIM39; the disease is long chain 3-hydroxyacyl-CoA dehydrogenase deficiency.