Is POLG a mitochondrial disease?

Is POLG a mitochondrial disease?

POLG mutations are the most common cause of inherited mitochondrial disorders, with as many as 2% of the population carrying these mutations. POLG-related disorders comprise a continuum of overlapping phenotypes with onset from infancy to late adulthood.

What is POLG mutation?

Mutations in the POLG gene are frequently responsible for an eye condition called progressive external ophthalmoplegia, another POLG-related disorder. This condition weakens the muscles that control eye movement and causes the eyelids to droop (ptosis).

How common is POLG mutation?

POLG mutations are relatively rare, with an estimated carrier frequency of 1/100 individuals in the Western world [11]. Most are recessive, and symptoms typically manifest only in compound heterozygous patients.

What is the life expectancy of mitochondrial disease?

A small study in children with mitochondrial disease examined the patient records of 221 children with mitochondrial disease. Of these, 14% died three to nine years after diagnosis. Five patients lived less than three years, and three patients lived longer than nine years.

What causes POLG disease?

It is an autosomal recessive disease caused by mutation in the gene for the mitochondrial DNA polymerase POLG.

What is a POLG related disorder?

POLG-related disorders comprise a continuum of broad and overlapping phenotypes that can be distinct clinical entities or consist of a spectrum of overlapping phenotypes. Presentations within a given family are usually similar.

Is POLG mutation fatal?

Alpers syndrome appears to be the most common autosomal recessive disease caused by mutations in the POLG gene. This early-onset fatal disease is characterized by intractable seizures, hepatic failure, and global neurological deterioration (Naviaux and Nguyen, 2004).

What causes POLG mutation?

In Alpers’ disease, mutations in POLG are inherited in an autosomal recessive fashion, typically from parents who are silent carriers. Homozygous or compound heterozygous mutations cause severe deficiency of polymerase γ, which leads to depletion of mitochondrial DNA with resulting mitochondrial dysfunction.

How does mitochondrial disease affect the brain?

Features: Brain abnormalities that can result in abnormal muscle tone, ataxia, seizures, impaired vision and hearing, developmental delays, and respiratory problems. Infants with the disease have a poor prognosis.

Where is POLG gene located?

The POLG gene is located on the long arm of chromosome 15, and encodes polymerase γ. Polymerase γ is the sole polymerase for mitochondrial DNA replication.

What does POLG stand for?

POLG (DNA Polymerase Gamma, Catalytic Subunit) is a Protein Coding gene. Diseases associated with POLG include Sensory Ataxic Neuropathy, Dysarthria, And Ophthalmoparesis and Mitochondrial Dna Depletion Syndrome 4A.

What are the different types of mitochondrial diseases?

The list of types of Mitochondrial diseases mentioned in various sources includes: Leber’s hereditary optic atrophy. Kearns-Sayre Syndrome. Progressive external ophthalmoplegia. Myoclonus epilepsy.

What are some examples of mitochondrial disorders?

Examples of mitochondrial diseases include: Mitochondrial myopathy. Diabetes mellitus and deafness (DAD) this combination at an early age can be due to mitochondrial disease. Diabetes mellitus and deafness can be found together for other reasons.

What diseases are in mitochondria?

Mitochondrial dysfunction occurs when the mitochondria do not work as well as they should due to another disease or condition. Many conditions can lead to secondary mitochondrial dysfunction and affect other diseases, including Alzheimer’s disease, muscular dystrophy, Lou Gehrig’s disease, diabetes and cancer.

What are symptoms of mitochondrial dysfunction?

Mitochondrial diseases present from early childhood to adulthood. Depending on the specific type of mitochondrial disease, common symptoms include muscle weakness, imbalance, gastrointestinal problems, poor growth, liver disease, heart disease, diabetes, visual and hearing issues, lactic acidosis , and developmental delays.