General Objective To investigate the bioenergetic profile of fibroblasts in selected energy deficiency type of IEM patients. Specific Objective(s) 1. To identify the gene of mutation in energy deficiency type of IEM patients. 2. To evaluate the bioenergetics profile using real time analysis assays. 3. To determine the mitochondrial morphology. 4. To determine the dynamic regulation of mitochondrial morphology. Study Design This observational, lab-based study that meet strict inclusion criteria. Sample prep: Cryopreserved patient and control fibroblasts are cultured and expanded for analysis. Mutation analysis: DNA is extracted, sequenced, and analyzed for relevant mutations. Bioenergetic profiling: Mitochondrial and glycolytic functions are measured and evaluated. Parameters include oxygen consumption and ATP production. Morphology assessment: Mitochondrial structure is visualized with immunofluorescence microscopy. Dynamics & protein assessment: Fusion and fission regulatory proteins (MFN1, MFN2, DRP1, OPA1) are measured by western blot and correlated with functional findings.