What Is a Mitochondrial Genome?

Mitochondria are organelles of eukaryotic cells and have their own genomes. These genomes are collectively called the mitochondrial genome. DNA in mitochondria can participate in protein synthesis, transcription, and replication, and has high research value

Mitochondrial genome

Mitochondria are organelles of eukaryotic cells and have their own

Mitochondria are organelles of eukaryotic cells and have their own

Mitochondria

Mitochondria

Compared to nuclear DNA, mtDNA acts as an organism

Human mitochondrial DNA (mtDNA) contains a total of 37 genes. Of these 37 genes, 22 encode transfer ribonucleic acid (tRNA), 2 encode ribosomal ribonucleic acid (12S and 16S rRNA), and 13 encode polypeptides. ^[3]

For patients with suspected mitochondrial disease, the ideal genetic diagnosis is to find mutations in genes that cause defects in mitochondrial structure and function. These gene mutations may be on mtDNA or nuclear genes. The inheritance of mitochondria may be autosomal stealth inheritance, X-linked inheritance, maternal inheritance, and some are new mutations. Due to the large number of genes involved in mitochondrial disease, currently only a few common mitochondrial gene loci can be selected for screening for mutations and deletions. The positive rate is very low, and most patients are difficult to obtain accurate etiology diagnosis.

The analysis of the mitochondrial genome requires analysis of 37 genes. Because the mitochondrial gene belongs to the maternal inheritance, the prenatal mitochondrial genome analysis of the mother is of great significance for the birth of healthy babies.

(1) 13 genes encoding polypeptides

Coded product	Genetic analysis	Gene variants for common mitochondrial diseases
NADH dehydrogenase (complex I)	MT-ND1	Leber's hereditary optic neuropathy
	MT-ND2	Myocardial mitochondrial disease, Leber's hereditary optic neuropathy
	MT-ND3	Enteroclonus, epilepsy, optic nerve atrophy
	MT-ND4	Leber hereditary optic neuropathy, mitochondrial myopathy, Leber hereditary optic neuropathy, dystonia
	MT-ND4L	Leber's hereditary optic neuropathy
	MT-ND5	Leigh syndrome, mitochondrial encephalomyopathy with lactic acidosis and stroke-like attack syndrome
	MT-ND6	Leber's hereditary optic neuropathy, mitochondrial encephalomyopathy with lactic acidosis and stroke-like attack syndrome, diabetes, dystonia
coenzyme Q-cytochrome c reductase / Cytochrome b (complex III)	MT-Cytb	Chronic migratory erythema, Leber's hereditary optic neuropathy, mitochondrial myopathy, myocardial mitochondrial disease, mitochondrial encephalomyopathy with lactic acidosis and stroke-like attack syndrome, Parkinson's disease
cytochrome c oxidase (complex IV)	MT-COX1	Myoglobinuria motor neuron disease, iron granulocyte anemia
	MT-COX2	Mitochondrial myopathy, mitochondrial multisystem disease, mitochondrial encephalomyopathy
	MT-COX3	Leigh syndrome, chronic migratory erythema, skeletal muscle lysis
ATP synthase	MT-ATP6	Ataxia with pigmented retinitis, maternal genetic Leigh syndrome, familial bilateral striatum necrosis
	MT-ATP8	Ibid

(2) 22 genes encoding tRNA

Alanine	MT-TA	Progressive extraocular muscle paralysis
Arginine	MT-TR
Asparagine	MT-TN	Mitochondrial myopathy, progressive extraocular muscle paralysis
Aspartic acid	MT-TD	Myocardial mitochondrial disease, myoclonus
Cysteine	MT-TC	Chronic migratory erythema
Glutamic acid	MT-TE	Myocardial mitochondrial disease, chronic migratory erythema
Glutamine	MT-TQ	Mitochondrial myopathy, mitochondrial encephalomyopathy with lactic acidosis and stroke-like attack syndrome
Glycine	MT-TG	Myocardial mitochondria, sudden infant death syndrome, chronic migratory erythema
Histidine	MT-TH
Isoleucine	MT-TI	Mitochondrial myopathy, myocardial mitochondrial disease, progressive extraocular muscle paralysis
Leucine	MT-TL1	Chronic progressive extraocular muscle paralysis, Leer hereditary optic neuropathy, mitochondrial encephalomyopathy with lactic acidosis and stroke-like attack syndrome, mitochondrial myopathy, myocardial mitochondrial disease, diabetes and mitochondrial deafness
	MT-TL2	Myocardial mitochondrial disease, chronic migratory erythema, chronic progressive extraocular muscle paralysis, mitochondrial myopathy, iron erythroblastic anemia
Lysine	MT-TK	Myocardial mitochondrial disease, chronic progressive extraocular muscle paralysis, myoclonic seizures with broken red fibers, mitochondrial encephalomyopathy with lactic acidosis and stroke-like attack syndrome, mitochondrial deafness
Methionine	MT-TM	Mitochondrial myopathy, lymphoma
Phenylalanine	MT-TF	Mitochondrial encephalomyopathy, lactic acidosis and stroke-like attacks, skeletal muscle lysis
Proline	MT-TP	Mitochondrial myopathy, progressive extraocular muscle paralysis
Serine	MT-TS1	Palmoplantar keratosis, mitochondrial deafness, myoclonic seizures with broken red fiber-mitochondrial encephalomyopathy with lactic acidosis and stroke-like episode
	MT-TS2	Diabetes and Mitochondrial Deafness
Threonine	MT-TT	Myocardial mitochondrial disease, chronic migratory erythema
Tryptophan	MT-TW	Leigh syndrome, ataxia chorea, mitochondrial myopathy
Tyrosine	MT-TY	Chronic progressive extraocular muscle paralysis
Valine	MT-TV	Leigh syndrome, mitochondrial encephalomyopathy with lactic acidosis and stroke-like attack syndrome, mitochondrial multisystem disease
12S ribosomal RNA	MT-RNR1	Parkinson's disease, aminoglycoside-induced deafness
16S ribosomal RNA	MT-RNR2	Myocardial mitochondrial disease

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