Expanding the phenotype of de novo ...
The SLC25A4 gene encodes the mitochondrial AAC1, which imports ADP into the mitochondrion and exports ATP. 5 Humans have 4 AAC isoforms, with AAC1 being specific to the heart, skeletal muscle, and brain. 6 Previous functional studies correlating the rate of ADP/ATP exchange with phenotype severity have only partially solved the puzzle.