Succinyl-CoA:3-oxoacid CoA transferase deficiency

Autosomal recessive - en

Succinyl-CoA:3-oxoacid CoA transferase (SCOT) deficiency is a rare metabolic disorder characterized by the body's inability to properly convert certain fats into energy. This condition, also known as ketone utilization disorder, specifically affects the process of ketolysis, which is crucial for energy production, especially during periods of fasting or increased energy demands.

Overview

SCOT deficiency is caused by mutations in the OXCT1 gene, which encodes the enzyme succinyl-CoA:3-oxoacid CoA transferase. This enzyme plays a key role in the ketone body metabolism pathway, facilitating the conversion of ketone bodies into acetyl-CoA, a vital component in the citric acid cycle for energy production. The absence or malfunctioning of this enzyme leads to an accumulation of ketone bodies, resulting in ketosis and potentially life-threatening ketoacidosis.

Symptoms

The symptoms of SCOT deficiency typically manifest in infancy or early childhood, often triggered by fasting or illnesses that increase the body's energy demands. Common symptoms include:

• Hypoglycemia (low blood sugar)
• Lethargy
• Vomiting
• Muscle weakness
• Seizures

If left untreated, SCOT deficiency can lead to severe metabolic crises, coma, and even death.

Diagnosis

Diagnosis of SCOT deficiency involves a combination of clinical evaluation, biochemical tests, and genetic testing. Biochemical tests may reveal elevated levels of ketone bodies in the blood and urine, particularly during episodes of metabolic stress. Genetic testing can confirm mutations in the OXCT1 gene, providing a definitive diagnosis.

Treatment

There is no cure for SCOT deficiency, but the condition can be managed through dietary modifications and careful monitoring of energy intake. Treatment strategies include:

• Avoidance of fasting and ensuring regular carbohydrate intake to minimize the risk of hypoglycemia and ketoacidosis.
• High-carbohydrate, low-fat diet to reduce the reliance on fat metabolism for energy.
• Emergency treatment with intravenous glucose solutions during metabolic crises to prevent severe ketoacidosis.

Prognosis

With early diagnosis and proper management, individuals with SCOT deficiency can lead relatively normal lives. However, they remain at risk for metabolic crises, particularly during periods of illness or fasting. Ongoing monitoring by a team of healthcare professionals specializing in metabolic disorders is essential for optimizing health and preventing complications.