Mitochondrial Disorders – How do they affect patients?

Mitochondrial disease results from dysfunction of mitochondria. Mitochondria are tiny structures which are present in every cell of the body (except red blood cells). The mitochondrion has been called the ‘powerhouse’ of the cell because these tiny structures produce most of the energy, which we all need to grow and live.

Those organs in the body which need lots of energy to work properly are most dependent on proper functioning mitochondria. The most energy dependent organs are the brain, heart, skeletal muscle, kidney, endocrine glands and bone marrow and these are the organ systems commonly affected by mitochondrial disorders.

Mitochondrial disease occurs when mitochondria do not work correctly. Mitochondrial disease often involve the brain due to the huge energy requirements of the brain cells. Mitochondrial diseases are very variable in their features and this is referred to as clinical heterogeneity.

Clinical heterogeneity is evident in most patients whom have very different symptoms. Some patients predominately suffer brain disease or nerve disease. Others will have muscle disease, known as mitochondrial myopathy, cardiac disease known as cardiomyopathies, endocrine, renal or bone marrow disease. Some patients have a mixture of these in addition to other features.

There is no convincing evidence to date of any clear benefit of drug therapies in most mitochondrial disorders or those neurodegenerative conditions with evidence of mitochondrial dysfunction, and therefore attention has turned to the development of genetic therapies.Although still in their infancy, genetic medicines are shining new hope on those living with mitochondrial disorders and other serious genetic conditions.

New horizons and hopes may lie with genetic strategies. Techniques for adapting the mitochondrial genome are now being investigated. Whereas nuclear manipulation would necessitate treatment for life, manipulation of the mitochondrial genome would result in a one-off treatment thus providing a cure for Mitochondrial Disorders.