Only 37 genes
Mitochondrial genome is contained in mitochondria, organelles responsible for cellular respiration. It is a small circular molecule present in a high number of copies. Mitochondrial genome has only 37 genes: 24 encode for transfer-RNA (tRNA) and ribosomal RNA (rRNA), while the other 13 genes are protein-coding. About 93% of mitochondrial DNA sequence is coding, as opposed to nuclear DNA, in which only 2% is coding.
Mitochondrial DNA structure
mtDNA is a double-stranded molecule of about 16,5 kb. It is extremely rich in G and C: the heavy strand (H) is G-rich and codes for 28 genes, while the light strand (L) is C-rich and codes for 9 genes. A small portion has a triple helix structure (DNA 7S structure). Polypeptides code for the subunits of the respiratory complexes, involved in oxidative phosphorylation and ATP production (although the vast majority of polypeptides involved in oxidative phosphorylation, which in total are about 110, are coded by the nuclear DNA). For more information about mitochondrial DNA and related disorders see mitochondrial inheritance.
Breda Genetics srl
Breda Genetics can analyze mitochondrial DNA in any exome or genome sequencing. Indeed, mitochondrial DNA produces a background signal which, through an appropriate bioinformatic pipeline, could be decoded and translated into a readable and interpretable sequence for diagnostic purposes.