Mitochondrial Complex Deficiency By Novel Compound Heterozygous Tmem70 Variants And Correlation With Developmental Delay, Undescended Testicle, And Left Ventricular Noncompaction In A Japanese Patient: A Case Report

Key Clinical Message We identified novel compound heterozygous TMEM70 variants in a Japanese patient who had hyperlactacidemia, metabolic acidosis, hyperalaninemia, developmental delay, undescended testicle, and left ventricular noncompaction. The urinary organic acids profile revealed elevated levels of 3-MGA, and BN-PAGE/Western blotting analysis and ETC. activity confirmed complex V deficiency.