Mitochondrial trifunctional protein deficiency

Mitochondrial trifunctional protein deficiency is a rare inherited condition that prevents the body from converting certain fats to energy, particularly during periods without food. People with this disorder have inadequate levels of an enzyme that breaks down a certain group of fats called long-chain fatty acids.

Onset of this disorder may begin during infancy or later in life. Signs and symptoms of the early onset form can include feeding difficulties, lack of energy (lethargy), low blood sugar (hypoglycemia), muscle weakness (hypotonia), liver problems, and a high risk for complications such as life-threatening heart and breathing problems, coma, and sudden unexpected death. The late-onset form is usually less severe; signs and symptoms can include hypotonia, muscle pain, a breakdown of muscle tissue, and abnormalities in the nervous system that affect arms and legs (peripheral neuropathy). Episodes of mitochondrial trifunctional protein deficiency can be triggered by periods of fasting or by illnesses such as viral infections. Mutations in the HADHA or HADHB genes can lead to inadequate levels of an enzyme complex known as mitochondrial trifunctional protein. Long-chain fatty acids from food and body fat cannot be metabolized and processed without sufficient levels of this enzyme complex. As a result, these fatty acids are not converted to energy, which can lead to characteristic features of this disorder, such as lethargy and hypoglycemia. Long-chain fatty acids or partially metabolized fatty acids may build up in tissues and damage the liver, heart, and muscles, causing more serious complications. The condition is inherited in an autosomal recessive pattern.

This article incorporates public domain text from The U.S. National Library of Medicine