Summary about Disease
Deficiency of palmitoyl-protein thioesterase 1 (PPT1) causes a neurodegenerative lysosomal storage disorder called neuronal ceroid lipofuscinosis type 1 (CLN1), also known as infantile Batten disease. It is a rare, inherited condition that primarily affects the nervous system. The deficiency of the PPT1 enzyme leads to the accumulation of lipofuscins (fatty, granular material) within cells, particularly in neurons, causing progressive loss of motor and cognitive functions.
Symptoms
Symptoms typically begin in infancy (around 6-18 months). Common symptoms include:
Developmental delay or regression
Myoclonic seizures (sudden muscle jerks)
Visual impairment or blindness
Microcephaly (small head size)
Motor impairment (ataxia, loss of motor skills)
Cognitive decline
Irritability or behavioral changes
Causes
CLN1 disease is caused by mutations in the PPT1 gene. This gene provides instructions for making the palmitoyl-protein thioesterase 1 enzyme. Mutations in this gene lead to a deficiency or absence of the PPT1 enzyme, resulting in the accumulation of storage material in cells, particularly neurons, eventually causing cell death. The disease is inherited in an autosomal recessive pattern, meaning an individual must inherit two copies of the mutated gene (one from each parent) to develop the condition.
Medicine Used
Currently, there is no cure for CLN1 disease. Treatment focuses on managing symptoms and providing supportive care to improve the quality of life. Medications used may include:
Antiepileptic drugs (AEDs) to control seizures
Muscle relaxants for spasticity
Pain medications for discomfort
Enzyme replacement therapy (ERT) : Cerliponase alfa is an enzyme replacement therapy approved to slow the loss of ambulation in symptomatic pediatric patients 3 years of age and older with late-infantile neuronal ceroid lipofuscinosis type 2 (CLN2) disease. Supportive care may include:
Physical therapy to maintain motor skills
Occupational therapy to improve daily living skills
Speech therapy to address communication difficulties
Nutritional support to ensure adequate nutrition
Palliative care to manage pain and other symptoms
Is Communicable
No, CLN1 disease is not communicable. It is a genetic disorder caused by inherited gene mutations and cannot be transmitted from person to person.
Precautions
Since CLN1 disease is a genetic condition, there are no specific precautions to prevent acquiring the disease. For families with a history of CLN1 disease, genetic counseling and testing are recommended to assess the risk of having a child with the condition. Carrier testing can identify individuals who carry one copy of the mutated gene, who are typically asymptomatic but can pass the gene to their offspring.
How long does an outbreak last?
CLN1 disease is not an outbreak. It is a chronic, progressive genetic condition, not an infectious disease.
How is it diagnosed?
Diagnosis of CLN1 disease typically involves:
Clinical evaluation: Review of symptoms, medical history, and neurological examination.
Enzyme assay: Measurement of PPT1 enzyme activity in blood or skin fibroblasts. Low or absent PPT1 activity is indicative of CLN1 disease.
Genetic testing: Sequencing of the PPT1 gene to identify mutations.
Brain imaging: MRI to assess brain structure and identify abnormalities.
Skin biopsy: To look for storage material.
Timeline of Symptoms
6-18 months: Onset of symptoms such as developmental delay/regression, myoclonic seizures.
Progressive: Gradual worsening of motor skills, cognitive abilities, and vision.
Childhood: Continued decline in neurological function, development of blindness, and feeding difficulties.
Late childhood/early adolescence: Most individuals with CLN1 disease require full-time care.
Death: Typically occurs in late childhood or adolescence due to complications such as pneumonia or respiratory failure.
Important Considerations
Early diagnosis is crucial for managing symptoms and providing appropriate supportive care.
Genetic counseling is recommended for families with a history of CLN1 disease.
Multidisciplinary care is essential, involving neurologists, geneticists, therapists, and palliative care specialists.
Support groups and resources are available for families affected by CLN1 disease.
Research is ongoing to develop new treatments and therapies for CLN1 disease.