MLYCD (malonyl-CoA decarboxylase) is a rare genetic disorder characterized by a deficiency of the enzyme malonyl-CoA decarboxylase. This enzyme is involved in the breakdown of fatty acids for energy production.

In individuals with MLYCD deficiency, the enzyme is either completely absent or present in very low levels. As a result, there is a buildup of malonyl-CoA, a molecule that inhibits the breakdown of fatty acids. This leads to a decrease in the production of energy from fatty acids.

Symptoms of MLYCD deficiency can vary widely and may include developmental delay, hypotonia (low muscle tone), seizures, feeding difficulties, failure to thrive, and cardiomyopathy (disease of the heart muscle). The severity of symptoms can also vary, with some individuals having mild symptoms while others have more severe manifestations.

MLYCD deficiency is inherited in an autosomal recessive manner, meaning that both parents must be carriers of the mutated gene for a child to be affected. Genetic testing can be done to confirm the diagnosis.

Treatment for MLYCD deficiency is mainly supportive and focuses on managing the symptoms. This may include a special diet low in long-chain fatty acids, supplementation with medium-chain triglycerides (which can be more easily metabolized), and medications to manage seizures or other symptoms. Regular monitoring by a healthcare team familiar with the condition is important to ensure optimal management and to address any complications that may arise.