Summary about Disease
Infantile Neuroaxonal Dystrophy (INAD) is a rare, progressive neurological disorder characterized by the accumulation of iron in the brain, specifically in the basal ganglia. This leads to progressive loss of motor and cognitive skills. It typically presents in infancy or early childhood. INAD is a type of neurodegeneration with brain iron accumulation (NBIA).
Symptoms
Symptoms vary but commonly include:
Developmental delay or regression (loss of previously acquired skills)
Hypotonia (low muscle tone) early on, often progressing to spasticity (increased muscle tone)
Vision problems, including nystagmus (involuntary eye movements) and optic atrophy
Seizures
Feeding difficulties
Intellectual disability
Involuntary movements such as dystonia (sustained muscle contractions) and choreoathetosis (writhing movements)
Skeletal abnormalities such as scoliosis
Causes
INAD is caused by genetic mutations, most commonly in the PLA2G6 gene. This gene provides instructions for making an enzyme called phospholipase A2 group VI (PLA2G6). Mutations in this gene disrupt the normal function of the enzyme, leading to abnormal lipid metabolism and iron accumulation in the brain. It is inherited in an autosomal recessive pattern, meaning both parents must carry a copy of the mutated gene for a child to be affected.
Medicine Used
There is no cure for INAD, and treatment focuses on managing symptoms and providing supportive care. Medications may include:
Muscle relaxants (e.g., baclofen, tizanidine) to help manage spasticity and dystonia
Anti-seizure medications to control seizures
Medications to manage feeding difficulties (e.g., anti-reflux medications)
Iron chelators: While iron accumulation is a hallmark of the disease, the effectiveness of iron chelators in INAD is still under investigation and not universally recommended.
Is Communicable
No, INAD is not communicable. It is a genetic disorder and cannot be spread from person to person.
Precautions
Since INAD is a genetic disorder, there are no specific precautions to prevent its occurrence. Genetic counseling is recommended for families with a history of INAD or related disorders who are planning to have children. Supportive care and managing complications such as aspiration pneumonia are important for affected individuals.
How long does an outbreak last?
INAD is not an infectious disease, so the concept of an "outbreak" does not apply. It is a chronic, progressive condition that lasts throughout the affected individual's life.
How is it diagnosed?
Diagnosis typically involves:
Clinical evaluation: Assessing symptoms, medical history, and family history.
Neurological examination: Assessing motor skills, reflexes, and cognitive function.
Brain MRI: To look for characteristic patterns of iron accumulation in the brain, particularly in the basal ganglia.
Genetic testing: To identify mutations in the PLA2G6 gene or other genes associated with NBIA.
Other tests: May include blood tests to rule out other conditions and electroencephalogram (EEG) to assess for seizure activity.
Timeline of Symptoms
The timeline of symptom onset and progression can vary significantly among individuals. However, a general timeline includes:
Infancy/Early Childhood: Onset of developmental delay or regression, hypotonia, vision problems (nystagmus), feeding difficulties.
Childhood: Progression of motor symptoms, including spasticity, dystonia, and choreoathetosis. Seizures may develop. Cognitive decline becomes more apparent.
Later Stages: Increasing disability, loss of mobility, and dependence on caregivers for all activities of daily living. Complications such as aspiration pneumonia and respiratory problems may occur.
Important Considerations
Early diagnosis is crucial for optimizing management and providing supportive care.
A multidisciplinary approach involving neurologists, geneticists, therapists (physical, occupational, speech), and other specialists is essential.
Supportive care includes managing symptoms, providing nutritional support, addressing respiratory problems, and preventing complications.
Genetic counseling is important for families affected by INAD.
Research is ongoing to better understand the disease and develop potential treatments.
Prognosis: INAD is a progressive and ultimately fatal disorder. Life expectancy varies but is often shortened.