MITOCHONDRIAL DISEASE TESTING

MITOCHONDRIAL DISEASE TESTING

Mitochondrial disease is a chronic, genetic disorder that occurs

when the mitochondria of the cell fail to produce enough energy for

cell or organ function. Mitochondrial disease result from failures

of the mitochondria, specialized compartments present in every cell

of the body.

More than 90% of the energy needed by the body are created

by the mitochondria. The energy produced by these mitochondria is

responsible for sustaining life and support organ function. That’s

why the mitochondria is known as the powerhouse of the cell.

If any failure occurs then only less and less amount of energy is generated

within the cell.this may lead to cell injury and cell death. The repetition

of this process leads to the failure of the whole organ system.

The failure will easily affect the parts of the body such as the heart,

brain, muscles, and lungs which require the greatest amount of energy. 

The main problem associated with this disease is it was very

difficult to diagnose because it affects each individual differently.

The main symptoms include seizures, strokes, severe developmental

delays, inability to walk, talk,see and digest food combined with

host of other complications.

Mitochondrial disease or disorders may be caused by mutations,

in mitochondrial DNA or in nuclear genes that code for

mitochondrial components. Also, these problems may be the

result of the acquired mitochondrial dysfunction due to the adverse

effects of drugs, infections or environmental causes.

There are several types of mitochondrial diseases. Examples of the mitochondrial disease include 

• Mitochondrial myopathy
• Diabetes mellitus and deafness
• Lebers hereditary optic neuropathy
• Leigh Syndrome
• Myoclonic epilepsy with ragged red fibers
• MEALS Syndrome
• Mitochondrial DNA depletion syndrome
• Myoneurogenic gastrointestinal encephalopathy

The diagnosis method of mitochondrial disease

Mitochondrial disease are usually detected by analyzing muscle samples,

where the presence of these organelles is higher. The most common tests

for the detection of these disease are 

• Southern blot to detect big deletions or duplications
• PCR and specific mutation analysis
• Sequencing

There are several laboratories all over the world where mitochondrial

disease testing has been done. Most diagnostic algorithms

recommended the evaluation of selected mitochondrial biomarkers

in blood, urine and spinal fluid. These typically include measurements

of lactate and pyruvate in plasma and cerebrospinal fluid, plasma,

urine and CSF amino acids, plasma acylcarnitines and urine

organic acids. Primary mitochondrial disorders are caused by mutations

in the maternally inherited mtDNA or one of many nDNA genes.

Although mitochondrial diseases are collectively common, the incidence

of each individual mitochondrial disease etiology or subtype is relatively rare.