Mitochondrial Diseases

Zoology Assignment

Mitochondrial Diseases

Submitted To Dr.Wajid

Submitted By Aaqib Chishti

University of Education Lahore, Okara Campus

University of Education Lahore, Okara Campus

Mitochondrial Diseases Unlike nuclear genes, which are inherited from

both parents, mitochondrial genes are inherited only from the mother.

• In mammals, 99.99% of mitochondrial DNA (mtDNA) is inherited from the mother. 

• This is because the sperm carries its mitochondria around a portion of its tail and has only about 100 mitochondria compared to 100,000 in the oocyte. 

MELAS Syndrome

•Mitochondrial: Mutation in the mitochondria•Encephalo: Occurs in the head•Myopathy: General term for muscle disease •Lactic Acidosis: The blood gets too acidic•Stroke-Like Episodes: Brain-Related ..

Symptoms of bleeding or blockage

University of Education Lahore, Okara Campus

Encephalomyopathy with Lactic Acidosis and Stroke-like Episodes

What Is MELAS .. ??

MELAS Syndrome

• It is the most common inherited mitochondrial disease• Clinical Features: Strokes, myopathy, muscle twitching, dementia (memory loss desease), and deafness• To a lesser extent: vomiting, migraine(severe) like headaches, diabetes, droopy eyelids, muscle weakness, and short stature• Presentation of the disease occurs with the first stroke-like episode (usually 14-15 years of age)• This is a progressive disorder with a high mortality rate

University of Education Lahore, Okara Campus

Characteristics

MELAS Syndrome

• Abnormal mitochondria do not metabolize pyruvate• Excess pyruvate is reduced to lactic acid which accumulates in blood and other fluids• Large abnormal mitochondria form in the walls of small arteries and capillaries in the brain and muscles

University of Education Lahore, Okara Campus

How does MELAS work?

What causes MELAS?• There are at least 6 different point mutations associated with MELAS• 80% of cases have a A to G point mutation in the tRNA gene at position 3243• 7.5% of cases have a T to C point mutation in the tRNA gene at position 3271

MELAS Syndrome

University of Education Lahore, Okara Campus

MELAS Syndrome

• All of these mutations are heteroplasmic• Heteroplasmic : within a single cell, there is a mixture of

mitochondria, some containing mutant DNA and some containing normal DNA

University of Education Lahore, Okara Campus

Further Details

Alex received his angel wings on Oct. 4, 2014 and battled MELAS for 11 years.

MERRF Syndrome

Myoclonus (brief, sudden, twitching muscle spasms - A

painful and involuntary muscular contraction) – the most characteristic symptoms

Epileptic seizures – (characteristic of epilepsy),(sudden occurrence of disease)

Ataxia - (unsteady movements and staggering gait) Ragged-red fibers (a characteristic microscopic abnormality observed in muscle of patients with MERRF and other mitochondrial disorders)

University of Education Lahore, Okara Campus

What is MERRF ??

Classic Features of MERRF ..

Myoclonic Epilepsy with Ragged Red Fibers is a mitochondrial disease that begins in childhood, but onset may occur in adulthood

MERRF Syndrome

University of Education Lahore, Okara Campus

Symptoms of MERRF

Short StatureLactic Acidosis – Elevated lactic acid level in the blood.

Cardiac Defects

Exercise Intolerance – Impatience with exercise

Dementia – Memory loss disease.

Speech Impairment - The condition of being unable to Speech as a consequence of physical or mental unfitness

Eye Abnormalities

Hearing Loss

MERRF Syndrome

University of Education Lahore, Okara Campus

Causes of MERRF The MERRF syndrome is caused by a maternally(from mother)-inherited mutation at position 8344 in the mitochondrial genome in over 80% of cases.

This mutation disrupts a mitochondrial gene for tRNA-Lys and so disrupts the synthesis of proteins essential for Oxidative Phosphorylation

Treatment of MERRF Like many mitochondrial diseases, there is no cure for MERRF

High doses of Coenzyme Q10 and L-Carnitine have been tried with little success as therapies in hopes of improving mitochondrial function.

Renal Oncocytoma

University of Education Lahore, Okara Campus

What is Renal Oncocytoma ??

A renal oncocytoma is a tumour of the kidney made up of oncocytes, a special kind of cell

Renal Oncocytoma

University of Education Lahore, Okara Campus

Description

discovered incidentally (by chance) on a tomography or ultrasound of the abdomen

Hematuria - The presence of blood in the urineFlank Pain – Region Between hip and ribs Abdominal Mass

These tumors are basically densely packed cells with mitochondria, which show morphologic differences from those in normal cells

Symptoms

It is characterized by benign tumour that occurs in different body parts but specially in kidneys

Renal Oncocytoma

University of Education Lahore, Okara Campus

Treatment Renal oncocytoma is considered benign, cured by nephrectomyis characterized by benign tumour that occurs in different body parts but specially in kidneys Nephrectomy – is the surgical removal of a kidney

The End