Summary about Disease
Fatty acid oxidation disorders (FAODs) are a group of inherited metabolic disorders that prevent the body from properly breaking down fats (fatty acids) to produce energy. This process, called fatty acid oxidation, is crucial, especially during periods of fasting, prolonged exercise, or illness when the body relies on stored fat for fuel. When fatty acid oxidation is impaired, the body cannot access this energy source, leading to a variety of symptoms, ranging from mild to life-threatening. FAODs are typically autosomal recessive, meaning both parents must carry a copy of the defective gene for a child to be affected.
Symptoms
Symptoms of FAODs vary depending on the specific disorder and the severity of the deficiency. Common symptoms include:
Lethargy and fatigue
Poor appetite and feeding difficulties in infants
Vomiting
Hypoglycemia (low blood sugar)
Muscle weakness (hypotonia)
Liver problems (hepatomegaly, elevated liver enzymes)
Heart problems (cardiomyopathy, arrhythmias)
Seizures
Developmental delays
Coma
Sudden infant death syndrome (SIDS) can be the first sign in some cases.
Causes
FAODs are caused by genetic mutations in genes that code for enzymes involved in the fatty acid oxidation pathway. These mutations result in a deficiency or complete absence of the enzyme, disrupting the breakdown of fats. Each specific FAOD is caused by a mutation in a different gene responsible for a particular enzyme in the pathway. FAODs are inherited in an autosomal recessive manner, meaning an affected individual inherits one mutated gene from each parent.
Medicine Used
There is no cure for FAODs, but management focuses on preventing metabolic crises and minimizing long-term complications. Treatment strategies include:
Dietary Modifications: A low-fat, high-carbohydrate diet is essential to provide the body with an alternative energy source. Frequent meals and snacks are necessary to prevent prolonged fasting.
L-Carnitine Supplementation: Carnitine helps transport fatty acids into the mitochondria (the energy-producing units of cells), where they can be metabolized. Supplementation can improve fatty acid metabolism in some individuals.
Medium-Chain Triglycerides (MCT) Oil: MCT oil can be used as a source of energy because it does not require the same enzymes as long-chain fatty acids for metabolism.
Emergency Protocol: During illness or stress, an emergency protocol is implemented, which typically includes increasing carbohydrate intake and potentially intravenous glucose administration to prevent metabolic decompensation.
Ravicti (glycerol phenylbutyrate): Medication used to treat certain urea cycle disorders.
Is Communicable
FAODs are not communicable. They are genetic disorders caused by inherited gene mutations and cannot be transmitted from person to person through any infectious means.
Precautions
Precautions for individuals with FAODs and their families center around preventing metabolic crises:
Strict Adherence to Dietary Guidelines: Following the prescribed low-fat, high-carbohydrate diet and ensuring frequent meals and snacks are crucial.
Avoiding Prolonged Fasting: Skipping meals or fasting for extended periods should be avoided.
Prompt Treatment of Illnesses: Any illness, even a minor one, can trigger a metabolic crisis. Medical attention should be sought immediately.
Emergency Plan: Develop and follow an emergency plan with clear instructions on how to manage illness or stress, including when to seek medical care and what medications to administer.
Inform Healthcare Providers: All healthcare providers, including doctors, dentists, and pharmacists, should be aware of the individual's FAOD to ensure appropriate treatment and avoid medications that could exacerbate the condition.
Newborn Screening: Early detection through newborn screening is vital for timely diagnosis and intervention.
Genetic Counseling: Families with a history of FAODs should consider genetic counseling to understand the risk of having affected children.
How long does an outbreak last?
FAODs do not involve outbreaks in the traditional sense of an infectious disease. Instead, individuals with FAODs can experience metabolic crises, which are episodes of metabolic decompensation triggered by illness, stress, or prolonged fasting. These crises can last from a few hours to several days, depending on the severity of the condition and the promptness of treatment.
Timeline of Symptoms
The timeline of symptom onset can vary greatly depending on the specific FAOD and its severity.
Newborn Period: Some severe FAODs can present in the first few days or weeks of life with symptoms such as lethargy, poor feeding, vomiting, hypoglycemia, and seizures.
Infancy and Early Childhood: Other FAODs may not become apparent until later in infancy or early childhood, often triggered by illness or periods of fasting. Symptoms may include developmental delays, muscle weakness, liver problems, and heart problems.
Adulthood: In rare cases, some milder FAODs may not be diagnosed until adulthood, with symptoms such as muscle pain, fatigue, or recurrent episodes of rhabdomyolysis (muscle breakdown).
Variable Expression: It's important to note that the severity and timing of symptoms can vary even within the same family.
Important Considerations
Early Diagnosis and Intervention: Early diagnosis through newborn screening and prompt management are crucial for improving outcomes and preventing long-term complications.
Lifelong Management: FAODs require lifelong management, including dietary modifications, medication (if needed), and close monitoring by a metabolic specialist.
Emergency Preparedness: Families need to be prepared for metabolic crises and have a clear plan in place for managing illness or stress.
Genetic Counseling: Genetic counseling is recommended for families with a history of FAODs to understand the risk of recurrence and discuss reproductive options.
Support Groups: Connecting with other families affected by FAODs can provide valuable support and information.
Individualized Treatment: Treatment plans should be tailored to the specific FAOD and the individual's needs and symptoms.
Adherence to dietary recommendations: Strictly adhering to diet and not skipping meals.
Education of caregivers: Ensure caregivers understand the importance of feeding schedules, emergency protocols, and signs of decompensation.