The main known mutations in this gene are c.317-2 A>G, located in the splice site of TMEM70 intron 2, which leads to aberrant splicing and loss of TMEM70 transcript, with most patients not surviving the neonatal period and the c.366A>T, (p.Tyr112Ter) resulting in Nuclear Type 2 Mitochondrial Complex V deficiency, showing HCM. Here, TMEM70 is linked to hyperinsulinemic hypoglycemia, familial, 4.