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.

1. An Overview about
MITOCHONDRIAL DISEASE TESTING

2. INTRODUCTION
❖ 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.

3. ❖ The energy produced by these mitochondria is responsible for sustaining
life and support organ function.
❖ Mitochondria is known as the powerhouse of the cell.

4. Cause of Mitochondrial Diseases
● 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.

5. Types of mitochondrial diseases
● 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

6. Diagnosis Method
❖ 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

7. Southern blot
● This is a laboratory test used to detect a specific DNA sequence in blood or
tissue sample.
● Various steps in southern blot
➢ DNA Digestion
➢ Gel Electrophoresis
➢ Blotting
➢ Probe labeling
➢ Hybridisation and Washing
➢ Detection

8. PCR and specific mutation analysis
➔ This is a technique which is used to make many copies of specific DNA
region.
➔ Various steps of PCR includes
◆ Denaturation
◆ Annealing
◆ Extension

9. CONCLUSION
❏ 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.