Friedreich's Ataxia
- 3. WHAT IS FRIEDREICH'S ATAXIA ?
Its an Autosomal Recessive Inherited Disease that
causes Progressive damage to the nervous system
,resulting in symptoms ranging from gait
diaturbances to speech problems,,It can lead to
Heart disease and diabetes
- 4. First described by Germen physician Nikolus
Friedreich in the 1860s
Incidence 1:50,000
Onset before age 20-25year
- 5. GENETICS
Mutations in the FXN gene cause Friedreich ataxia.
This gene provides instructions for making a protein
called frataxin. Although its role is not fully
understood, frataxin is important for the normal
function of mitochondria,
the energy-producing centers within cells. One
region of the FXN gene contains a segment of DNA
known as a GAA trinucleotide repeat.
- 6. In people with Friedreich ataxia, the GAA segment
is repeated 66 to more than 1,000 times. The length
of the GAA trinucleotide repeat appears to be
related to the age at which the symptoms of
Friedreich ataxia appear, how severe they are, and
how quickly they progress. People with GAA
segments repeated fewer than 300 times tend to
have a later appearance of symptoms (after age
25) than those with larger GAA trinucleotide
repeats.
- 7. The abnormally long GAA trinucleotide repeat
disrupts the production of frataxin, which severely
reduces the amount of this protein in cells. Certain
nerve and muscle cells cannot function properly
with a shortage of frataxin, leading to the
characteristic signs and symptoms of Friedreich
ataxia.
- 8. PATHOLOGY
Primary site of pathology is Spinal cord and
peripheral Nerves
Degeneration of nerve tissue in the spinal cord,
In particular sensory nuerons essential(through
connections with the cerebellum) for directing
muscle movement of the arms and legs
The spinal cord becomes thinner and nerve cells lose
of their myelin sheath
- 9. SIGNS AND SYMPTOMS
dysarthria,
muscle weakness,
spasticity particularly in the lower limbs, scoliosis,
bladder dysfunction,
absent lower limb reflexes, and loss of position and
vibration sense
Diabetes (about 20% of people with friedrich ataxia
develop carbohydrate intolerance and 10% of
Diabetes Mellitus
Heart disorder (Atrial Fibrillation,Cardiomyopathy
,Tachycardia
- 10. DIAGNOSIS
Typically, diagnosis begins with a basic physical
exam and a careful assessment of personal and
family history.
During the physical exam, the neurologist is likely to
devote special time and attention to testing
reflexes, including the knee-jerk reflex. Loss of
reflexes occurs in most people with FA.
Tests for frataxin mutations are highly reliable and
can be used to confirm or exclude a diagnosis of FA
in almost all cases.
- 11. Electromyography (EMG) is done by inserting a
needlelike electrode into a muscle and recording
the electrical signals it generates during contraction
A computerized tomography (CT scan) or magnetic
resonance imaging (MRI) might be performed to
look for extensive changes in the cerebellum, which
are more common in spinocerebellar ataxias than in
FA.nerve conduction velocity test (NCV)
- 13. TREATMENT’
FA is a disease with multisystem involvement
so multidisciplinary action is needed
This should include
NEUROLOGIST
GENETICIST AND GENETIC COUNSELLOR
PHYSIOTHERAPISTS
SPEECH AND LANGAUGE THERAPISITS AND
ALSO CARDIOLOGIST,ORTHOPAEDICS
- 14. TREATMENT
DRUG THERAPY:
1) IDEBENONE:
short chain quinine analogue
act as potent antioxidant and electron
carrier
2)Deferiprone
3)Erythropoietin,pioglitazone
SUPPORTIVE THERAPY
Physiotherapy and mobility aids
treatment for cardiac failure
orthopedic surgery (scoliosis),Diabetics etc