Types of Mitochondrial Diseases

ADOA: Autosomal Dominant Optic Atrophy

Autosomal Dominant Optic Atrophy is a neuro-ophthalmic condition that tends to begin in the first ten years of life and is characterized by degeneration of the optic nerves, causing visual loss. The severity of the disease is highly variable, with the visual acuity ranging from normal to legal blindness. About 20% of DOA patients present with additional multi-systemic features, including neurosensory hearing loss, or less common chronic progressive external ophthalmoplegia, myopathy, peripheral neuropathy, multiple sclerosis-like illnesses, spastic paraplegia, or cataracts.

Alpers Disease

Alpers disease is a rare mitochondrial condition where the protein that helps replicate and repair the mitochondrial DNA does not work as well as it should. Mitochondria are parts of a cell that help turn the energy we get from food into energy that the body can use. They are also important in the communication between body parts and in creating other materials the body needs.

Barth Syndrome

Barth syndrome is a rare mitochondrial condition where a protein on the mitochondrial membrane doesn’t work as well as it should, resulting in immature cardiolipin production. Cardiolipin is important for the structure and organization of the mitochondria as well as cell death. Mitochondria are parts of a cell that help turn the energy we get from food into energy that the body can use. They are also important in the communication between body parts and creating other materials the body needs. Mitochondrial conditions can cause a variety of signs and symptoms in many parts of the body, particularly those that use a lot of energy like muscles and the brain.

Carnitine Deficiency

Carnitine Deficiency – certain fats cannot be utilized for energy, particularly during periods of fasting. Carnitine, a natural substance acquired mostly through the diet, is used by cells to process fats and produce energy. Clinical symptoms typically appear during infancy or early childhood and can include severe brain dysfunction (encephalopathy), a weakened and enlarged heart (cardiomyopathy), confusion, vomiting, muscle weakness, and low blood sugar (hypoglycemia). The severity of this condition varies among affected individuals. Individuals with this disorder are at risk for heart failure, liver problems, coma, and sudden death. Treatment includes avoidance of fasting and carnitine supplementation.

CDD: Creatine Deficiency Syndromes

The creatine deficiency disorders (CDDs), inborn errors of creatine metabolism and transport, comprise three disorders:

1. Guanidinoacetate methyltransferase (GAMT) deficiency
2. L-arginine:glycine amidinotransferase (AGAT) deficiency
3. Creatine transporter (CRTR) deficiency