In Fatty Acid Oxidation DisordersA group of genetic conditions that affect how the body breaks down fats to make energy. (FAODs), the body suffers from an energy deficiency during conditions such as fasting, prolonged exercise and infection. This creates a metabolic stress for the body and causes the symptoms characteristic of FAOD. Some severe FAODs can present in infancy but symptoms can differ based upon age, diagnosis and the severity of the metabolic stress.
Common symptoms associated with FAODs include:
- Muscle cramps and pain
- Muscle weakness
- FatigueThe overall feeling of tiredness or lack of energy. It is not the same as simply feeling drowsy or sleepy. Being fatigued means having no motivation or energy.
- Foggy thinking
- Irritability
- Vomiting
- Poorly functioning heart (cardiomyopathyAn abnormal condition of the heart muscle. Occurs in some kinds of mitochondrial disease. or arrhythmias)
- Fatty, dysfunctional liver
Caregivers and patients with FAODs should be aware of and watch for symptoms of a metabolic crisis including:
- Acute muscle pain and weakness
- Poor feeding or changes in appetite
- Lethargy or unresponsiveness
- Irregular heartbeat
Symptoms can be triggered or worsened by fasting, illness, prolonged exercise, and other physiological stress. These factors can lead to the following if not managed:
- Low glucose or low sugar (hypoglycemiaLow blood sugar.), and usually low ketonesBy-products formed when the body breaks down fat for energy. The ketones can accumulate in the blood and an excessive amount of ketones is called ketosis.
- Muscle breakdown (rhabdomyolysisBreakdown of muscle tissue, releasing muscle fiber contents into the blood, with complex and potentially fatal consequences. Muscle contents are harmful to the kidney; rarely, permanent muscle damage), presenting as dark urine (myoglobinuriaA breakdown of muscle after exercise or muscle injury. That causes leakage of a protein called myoglobin from the muscles into the urine. This occurrence stresses the kidney's ability to filter waste)
- Heart muscle damage (cardiomyopathy or arrhythmias)
Sudden Infant Death Syndrome (SIDS) can occur in certain FAODs, usually in undiagnosed infants. Newborn screening helps identify patients before they become symptomatic, reducing the chance of illness and death.
You should always consult your medical team if you or your child experience severe symptoms in order to determine the best course of action.
