SNP Shot: Genomic Insights

ACAD9 deficiency presents with a range of symptoms, from mild to severe, potentially impacting muscle strength, heart function, and cognitive abilities. Lactic acidosis, an accumulation of lactic acid, is almost always present. In some cases, additional symptoms affecting other organs can occur.

Individuals with mild ACAD9 deficiency often experience nausea and significant fatigue following physical exertion, a condition known as exercise intolerance. Those with moderate deficiency display reduced muscle tone (hypotonia) and muscle weakness, particularly in skeletal muscles. The most severely affected experience brain dysfunction alongside myopathy (encephalomyopathy). They also commonly develop hypertrophic cardiomyopathy, an enlarged and weakened heart, which typically leads to death in infancy or early childhood.

Individuals with ACAD9 deficiency who survive beyond early childhood frequently experience intellectual disability and may develop seizures. Less common symptoms include movement disorders and liver or kidney problems.

Some individuals with ACAD9 deficiency have shown improvement in muscle strength and reduced lactic acid levels with appropriate treatment.

Inheritance:

ACAD9 deficiency follows an autosomal recessive inheritance pattern. This means that an individual must inherit a mutated copy of the ACAD9 gene from both parents to develop the condition. The parents, who each carry one copy of the mutated gene, usually do not exhibit any symptoms of ACAD9 deficiency.