Hydrolyzes inorganic pyrophosphate (PubMed:27523597). This activity is essential for correct regulation of mitochondrial membrane potential, and mitochondrial organization and function (PubMed:27523598). diphosphate + H2O = H(+) + 2 phosphate Homodimer. Detected in brain, gastric carcinoma, lung, ovary, skeletal muscle, umbilical cord blood and a cell line derived from kidney proximal tubule epithelium. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Belongs to the PPase family. Truncated N-terminus. Aberrant splicing. Truncated C-terminus. Intron retention. Truncated N-terminus.