Table 1.

The major types of genetic mutation or deletion cause primary mitochondrial myopathies.

Myopathy	Gene of Mutation	nDNA/mtDNA	Muscle and Mitochondria Phenotypes	Reference
CPEO	POLG1, POLG2, ATN1, C10ORF2, Opa1, TK2, and multiple mtDNA or mtRNA	nDNA/mtDNA	mitochondria with swollen cristae or paracrystalline inclusions. Reduce mitochondria respiration capacity. Increase ROS generation. Mitochondria fusion defect.	[167,174,176]
TK-2 DEFICIENCY	TK2	nDNA	Selective loss of type II fiber. Increase the proportion of SDH staining positive fiber and Cox staining negative fiber.	[177]
KEARNS-SAYRE SYNDROME	Variable single mtDNA deletion	mtDNA	Reduce mitochondria respiration activity.	[169]
MELAS	MT-TL1, MT-TH, MT-TV, MT-ND5, and MT-ND5	mtDNA	Enlarged mitochondria or slightly swollen small mitochondria. Reduce mitochondria respiration activity and increase ROS generation.	[168,178]
MERRF	MT-TK, MT-TL1, MT-TH, and MT-TS1	mtDNA	Reduce mitochondria respiration activity, increase ROS generation, ROS clearance defect.	[170,178,179,180]
COQ10 DEFICIENCY	COQ2, COQ4, COQ6, COQ7, COQ8A, COQ8B, COQ9, PDSS1, and PDSS2	nDNA	Reduce mitochondria respiration activity.	[171]
LEIGH SYNDROME	ND2, and SURF1	nDNA	Reduce mitochondria respiration activity, reduce mitochondria complex I activity.	[172]