Summary about Disease
Succinyl-CoA ligase [ADP-forming] deficiency (also known as succinate thiokinase deficiency, ADP-forming) is a very rare inherited metabolic disorder that disrupts the body's ability to produce energy from food. Specifically, it affects the citric acid cycle (Krebs cycle), a crucial process within mitochondria (the energy-producing centers of cells). This deficiency leads to a buildup of toxic substances in the body, especially affecting tissues with high energy demands like the brain, muscles, and heart.
Symptoms
Symptoms are variable but can include:
Muscle weakness (hypotonia)
Failure to thrive (poor weight gain and growth)
Developmental delay
Seizures
Enlarged heart (cardiomyopathy)
Enlarged liver (hepatomegaly)
Lactic acidosis (buildup of lactic acid in the blood)
Neurological problems (e.g., ataxia, intellectual disability)
Causes
The deficiency is caused by mutations in the SUCLA2 gene. This gene provides instructions for making a subunit of the succinyl-CoA ligase [ADP-forming] enzyme. Mutations in this gene result in a non-functional or less functional enzyme, disrupting the citric acid cycle. It is inherited in an autosomal recessive pattern, meaning both parents must carry a copy of the mutated gene for the child to be affected.
Medicine Used
There is no specific cure for succinyl-CoA ligase [ADP-forming] deficiency. Treatment focuses on managing symptoms and preventing complications. Medical interventions can include:
Dietary modifications: Low protein diets.
Supplements: Biotin supplements.
Medications: To control seizures.
Is Communicable
No. Succinyl-CoA ligase [ADP-forming] deficiency is a genetic disorder and is not contagious or communicable. It cannot be spread from person to person.
Precautions
Precautions focus on managing the condition and preventing crises:
Strict adherence to the prescribed diet.
Regular monitoring of blood lactate levels.
Prompt treatment of illnesses to prevent metabolic decompensation.
Genetic counseling for families.
How long does an outbreak last?
This is not an infectious disease. There are no outbreaks associated with it. The condition is chronic and lifelong, requiring ongoing management.
How is it diagnosed?
Diagnosis typically involves:
Clinical evaluation: Assessment of symptoms and family history.
Blood tests: To measure levels of lactic acid, organic acids, and amino acids.
Urine tests: To analyze organic acids.
Enzyme assay: Measuring the activity of succinyl-CoA ligase [ADP-forming] in cells (e.g., fibroblasts).
Genetic testing: To identify mutations in the SUCLA2 gene.
Muscle biopsy: To assess for mitochondrial abnormalities.
Timeline of Symptoms
The onset and progression of symptoms can vary. Some individuals may present with symptoms in infancy, while others may not develop noticeable symptoms until later in childhood. The timeline depends on the severity of the enzyme deficiency and the individual's response to treatment.
Important Considerations
Early diagnosis and intervention are crucial to minimize long-term complications.
Management requires a multidisciplinary approach involving specialists in genetics, metabolism, neurology, and cardiology.
Prognosis is variable and depends on the severity of the deficiency and the effectiveness of treatment.
Genetic counseling is important for families with affected individuals to understand the risk of recurrence in future pregnancies.