Any mitochondrial complex deficiency in which the cause of the disease is a mutation in the TMEM70 gene. It is characterized by early neonatal onset of hypotonia, hypetrophic cardiomyopathy and apneic spells within hours after birth accompanied by lactic acidosis, hyperammonemia and 3-methylglutaconic aciduria. The disease is Monarch Disease Ontology identifier MONDO_0013546 (mitochondrial complex V (ATP synthase) deficiency, nuclear type 2). Also known as: MC5DN2, mitochondrial encephalo-cardio-myopathy due to F1Fo ATPase deficiency, mitochondrial encephalo-cardio-myopathy due to isolated ATP synthase deficiency, mitochondrial encephalo-cardio-myopathy due to isolated mitochondrial respiratory chain complex V deficiency, neonatal mitochondrial encephalocardiomyopathy due to ATP synthase deficiency.