Summary about Disease
Very-long-chain acyl-CoA dehydrogenase deficiency (VLCADD) is an inherited metabolic disorder that prevents the body from properly breaking down certain fats, particularly very-long-chain fatty acids. This can lead to energy deficiencies, especially during periods of fasting or illness. VLCADD is an autosomal recessive disorder, meaning both parents must carry a copy of the defective gene for their child to inherit the condition. Severity varies, with some individuals experiencing severe symptoms in infancy and others remaining asymptomatic until adulthood.
Symptoms
Symptoms of VLCADD can vary widely based on the age of onset and severity of the deficiency. Possible symptoms include:
Hypoglycemia (low blood sugar)
Lack of energy (lethargy)
Muscle weakness (hypotonia)
Enlarged liver (hepatomegaly)
Heart problems (cardiomyopathy, arrhythmias)
Failure to thrive (in infants)
Rhabdomyolysis (muscle breakdown) triggered by exercise or illness
Coma
Sudden death (especially in infants)
Causes
VLCADD is caused by mutations in the ACADVL gene. This gene provides instructions for making the very-long-chain acyl-CoA dehydrogenase (VLCAD) enzyme. This enzyme is responsible for the first step in beta-oxidation, a process that breaks down very-long-chain fatty acids inside the mitochondria of cells to produce energy. When the *ACADVL* gene is mutated, the enzyme is either not produced or is not functional. This prevents the body from properly utilizing long-chain fats for energy, leading to the accumulation of these fats and the development of VLCADD symptoms.
Medicine Used
There is no specific cure for VLCADD. Management focuses on preventing metabolic crises and providing alternative energy sources. Common treatments include:
Dietary Management: A diet low in long-chain fats and supplemented with medium-chain triglycerides (MCT oil), which are easier to metabolize.
Frequent Feedings: Avoiding long periods without food is crucial, especially for infants. Cornstarch can be used to stabilize blood sugar levels overnight.
L-Carnitine supplementation: May help remove accumulated fatty acids.
Emergency Protocol: During illness or stress, intravenous glucose may be needed to prevent hypoglycemia and metabolic crises.
Is Communicable
No, VLCADD is not communicable. It is a genetic disorder caused by a mutation in the ACADVL gene and is inherited from parents. It cannot be spread from person to person.
Precautions
Precautions for individuals with VLCADD and their families include:
Strict Adherence to Dietary Guidelines: Consistently following the prescribed diet is crucial.
Avoiding Prolonged Fasting: Maintaining regular feeding schedules is essential.
Emergency Preparedness: Having an emergency protocol in place for illness or stress, including readily available glucose sources and instructions for medical personnel.
Monitoring for Symptoms: Vigilantly watching for early signs of metabolic crises and seeking prompt medical attention.
Genetic Counseling: Considering genetic counseling for family planning to assess the risk of having another child with VLCADD.
Medical Alert Bracelet: Wear a medical alert bracelet that lists the condition and emergency contact information.
How long does an outbreak last?
VLCADD is not an infectious disease and does not have "outbreaks" in the traditional sense. Metabolic crises can occur due to illness, fasting, or stress, and the duration of these events varies depending on the severity of the crisis and the promptness of medical intervention. With proper management, individuals with VLCADD can live normal lifespans.
How is it diagnosed?
VLCADD is typically diagnosed through:
Newborn Screening: Many states include VLCADD in their newborn screening programs, which involves analyzing a blood sample for specific metabolites.
Acylcarnitine Profile: A blood test that measures the levels of various acylcarnitines, which are elevated in individuals with VLCADD.
Urine Organic Acid Analysis: Analyzing urine for abnormal organic acids, which can indicate metabolic disorders.
Enzyme Assay: Measuring the activity of the VLCAD enzyme in blood cells or skin fibroblasts.
Genetic Testing: Sequencing the ACADVL gene to identify mutations.
Timeline of Symptoms
The timeline of symptoms varies depending on the severity of the VLCADD.
Severe Infantile Form: Symptoms such as hypoglycemia, lethargy, hypotonia, and cardiomyopathy can appear within the first few months of life.
Later-Onset Form: Symptoms may not appear until childhood or adulthood, often triggered by illness, fasting, or exercise. These can include muscle pain, weakness, and rhabdomyolysis.
Asymptomatic: Some individuals with VLCADD may remain asymptomatic throughout their lives, especially if they adhere to dietary guidelines and avoid triggers.
Important Considerations
Early Diagnosis and Management: Early diagnosis and initiation of dietary management are crucial for improving outcomes and preventing complications.
Individualized Treatment: Management strategies should be tailored to the individual's specific needs and symptoms.
Lifelong Management: VLCADD requires lifelong dietary management and monitoring.
Awareness Among Healthcare Professionals: It is important for healthcare professionals to be aware of VLCADD and its potential complications, especially during periods of illness or stress.
Family Support: Support groups and resources for families affected by VLCADD can be helpful in managing the condition.