An overview about mitochondrial disease testing

An Overview about MITOCHONDRIAL DISEASE TESTING

INTRODUCTION â?– 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. â?– Mitochondrial disease result from failures of the mitochondria, specialized compartments present in every cell of the body. â?– More than 90% of the energy needed by the body are created by the mitochondria.

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

Cause of Mitochondrial Diseases â—?

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Mitochondrial disease or disorders may be caused by mitochondrial DNA or in nuclear genes that code for components.

Also, these problems may be the result of the acquired dysfunction due to the adverse effects of drugs, infections or causes.

mutations, in mitochondrial mitochondrial environmental

Types of mitochondrial diseases ●

Mitochondrial myopathy

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Diabetes mellitus and deafness

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Lebers hereditary optic neuropathy

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Leigh Syndrome

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Myoclonic epilepsy with ragged red fibers

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MEALS Syndrome

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Mitochondrial DNA depletion syndrome

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Myoneurogenic gastrointestinal encephalopathy

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

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PCR and specific mutation analysis

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Sequencing

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

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

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Annealing

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Extension

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.