How Incurable Mitochondrial Diseases Strike Previously Unaffected Families

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Researchers have shown for the first time how children can inherit a severe – potentially fatal – mitochondrial disease from a healthy mother. The study, led by researchers from the MRC Mitochondrial Biology Unit at the University of Cambridge, reveals that healthy people harbour mutations in their mitochondrial DNA and explains how cases of severe mitochondrial disease can appear unexpectedly in previously unaffected families.

Researchers have shown for the first time how children can inherit a severe – potentially fatal – mitochondrial disease from a healthy mother. The study, led by researchers from the MRC Mitochondrial Biology Unit at the University of Cambridge, reveals that healthy people harbour mutations in their mitochondrial DNA and explains how cases of severe mitochondrial disease can appear unexpectedly in previously unaffected families.

Mitochondrial diseases caused by mutations in mitochondrial DNA are rare, affecting approximately 1 in 10,000 births, but can cause severe conditions. For example, Leigh syndrome is a severe brain disorder causing progressive loss of mental and movement abilities, which usually becomes apparent in the first year of life and typically results in death within two to three years.

Mitochondria are the powerhouses inside our cells, producing energy and carrying their own DNA instructions (separate from the DNA in the nucleus of every cell). Mitochondria are inherited from a person’s mother via the egg.

In the study, published in Nature Cell Biology, the researchers isolated mouse and human female embryonic germ cells – the cells that will go on to be egg cells in an adult woman – and tested their mitochondrial DNA.

Read more at Medical Research Council

Image: Illustration of mitochondria.  (Credit: MRC MBU)