Human mitochondrial genetics

Human mitochondrial DNA
The 16,569 bp long human mitochondrial genome with the protein-coding (red, orange, yellow), ribosomal RNA (blue), and transfer RNA genes (white). Non-coding mtDNA control region in grey.
Features
Length (bp)	16,569
No. of genes	13 (coding genes) 24 (non coding genes)
Type	Mitochondrial DNA
Complete gene lists
HGNC	Gene list
NCBI	Gene list
External map viewers
Ensembl	Chromosome MT
Entrez	Chromosome MT
NCBI	Chromosome MT
UCSC	Chromosome M
Full DNA sequences
RefSeq	NC_012920 (FASTA)
GenBank	J01415 (FASTA)

Human mitochondrial genetics is the study of the genetics of human mitochondrial DNA (the DNA contained in human mitochondria). The human mitochondrial genome is the entirety of hereditary information contained in human mitochondria. Mitochondria are small structures in cells that generate energy for the cell to use, and are hence referred to as the "powerhouses" of the cell.

Mitochondrial DNA (mtDNA) is not transmitted through nuclear DNA (nDNA). In humans, as in most multicellular organisms, mitochondrial DNA is inherited only from the mother's ovum. There are theories, however, that paternal mtDNA transmission in humans can occur under certain circumstances.^[3] Mitochondrial inheritance is therefore non-Mendelian, as Mendelian inheritance presumes that half the genetic material of a fertilized egg (zygote) derives from each parent.

This allowed the creation of mitochondrial DNA haplogroups to study population genetics.

Eighty percent of mitochondrial DNA codes for mitochondrial RNA, and therefore most mitochondrial DNA mutations lead to functional problems, which may be manifested as muscle disorders (myopathies).

Because they provide 30 molecules of ATP per glucose molecule in contrast to the 2 ATP molecules produced by glycolysis, mitochondria are essential to all higher organisms for sustaining life. The mitochondrial diseases are genetic disorders carried in mitochondrial DNA, or nuclear DNA coding for mitochondrial components. Slight problems with any one of the numerous enzymes used by the mitochondria can be devastating to the cell, and in turn, to the organism.