Summary about Disease
Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHAD) is a rare genetic disorder that prevents the body from properly breaking down certain fats (long-chain fatty acids) to produce energy. This can lead to a shortage of energy, particularly during periods of fasting or illness. The body relies on fat metabolism for energy, especially when glucose stores are depleted. LCHAD specifically impacts the enzyme long-chain 3-hydroxyacyl-CoA dehydrogenase, which is crucial for a specific step in this fat breakdown process within mitochondria.
Symptoms
Symptoms can vary in severity and age of onset, but commonly include:
Hypoketotic hypoglycemia (low blood sugar without ketones)
Muscle weakness (hypotonia)
Liver problems (hepatomegaly)
Heart problems (cardiomyopathy, arrhythmias)
Peripheral neuropathy (nerve damage in hands and feet)
Rhabdomyolysis (muscle breakdown)
Retinopathy (eye problems)
Failure to thrive in infancy
Causes
LCHAD is caused by mutations in the HADHA gene, which provides instructions for making part of the trifunctional protein complex, which includes long-chain 3-hydroxyacyl-CoA dehydrogenase. 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
4. Medicine used There is no cure for LCHAD. Treatment focuses on managing the symptoms and preventing metabolic crises. This typically involves:
Dietary management: A strict diet low in long-chain fats and high in carbohydrates, with frequent meals and snacks to avoid fasting. Medium-chain triglyceride (MCT) oil may be used as a supplemental source of energy.
Carnitine supplementation: Carnitine helps transport fatty acids into the mitochondria. Supplementation may improve some symptoms.
Emergency protocol: Parents are educated about recognizing early symptoms of a metabolic crisis and given a plan to follow, which may involve hospital admission for intravenous glucose administration.
Avoidance of fasting: Strategies to avoid prolonged periods without food are critical.
Is Communicable
No, LCHAD is not communicable. It is a genetic disorder, not an infectious disease.
Precautions
Strict adherence to dietary guidelines: Consistent monitoring and adjustment of the diet are essential.
Avoidance of prolonged fasting: Regular meals and snacks, especially during illness or periods of increased physical activity.
Prompt medical attention during illness: Any illness, even a minor cold, can trigger a metabolic crisis. Early treatment is crucial.
Newborn screening: If a family has a history of LCHAD, newborn screening can help with early detection and management.
Genetic counseling: For families with a history of LCHAD, genetic counseling can help determine the risk of having another affected child.
How long does an outbreak last?
LCHAD is not an "outbreak" type of disease. It is a chronic, genetic condition. Metabolic crises can occur sporadically and can last for several days, depending on the severity and promptness of treatment. These crises are often triggered by illness or fasting.
How is it diagnosed?
Diagnosis typically involves:
Newborn screening: Many states include LCHAD in their newborn screening programs, which involves a blood test to check for elevated levels of specific acylcarnitines.
Acylcarnitine profile: Blood or urine tests to measure levels of different acylcarnitines. Elevated levels of specific acylcarnitines are suggestive of LCHAD.
Urine organic acid analysis: Measures organic acids in the urine, which may be abnormal in LCHAD.
Enzyme assay: Measures the activity of long-chain 3-hydroxyacyl-CoA dehydrogenase in fibroblasts or lymphocytes.
Genetic testing: Confirms the diagnosis by identifying mutations in the HADHA gene.
Timeline of Symptoms
9. Timeline of symptoms The onset and progression of symptoms vary.
Newborn period: Symptoms may be present at birth or develop within the first few months of life.
Infancy: Symptoms like hypoketotic hypoglycemia, hypotonia, and liver problems often manifest during infancy.
Childhood/Adulthood: If the condition is milder or undiagnosed, symptoms may not appear until childhood or even adulthood, often triggered by fasting or illness. Long-term complications like peripheral neuropathy and retinopathy can develop over time.
Important Considerations
Early diagnosis and management are critical: Early intervention can significantly improve the prognosis and reduce the risk of complications.
Lifelong management is necessary: LCHAD requires ongoing dietary management, monitoring, and emergency planning.
Multidisciplinary care: Management involves a team of healthcare professionals, including a metabolic specialist, dietitian, cardiologist, neurologist, and ophthalmologist.
Parental education and support: Parents need to be educated about the disease, its management, and the importance of strict adherence to the treatment plan. Support groups and online resources can provide valuable information and emotional support.
Potential for complications: Even with optimal management, complications like cardiomyopathy, peripheral neuropathy, and retinopathy can still occur. Regular monitoring is essential to detect and manage these complications early.