TRIM39 and hyperinsulinemic hypoglycemia, familial, 4: Fibroblasts from patients with HADHA variants—FB822 (homozygous common LCHAD variant) and FB847 (compound heterozygous variants leading to complete TFP deficiency)—showed higher ROS levels than control fibroblasts (FB826), whereas FB861 cells with compound heterozygous HADHB variants had ROS levels comparable to control cells (Figure 5A).