MEGDEL syndrome is an inherited disorder that affects multiple body systems. It is named for several of its features: 3-methylglutaconic aciduria (MEG), deafness (D), encephalopathy (E), and Leigh-like disease (L).
MEGDEL syndrome is a rare disorder; its prevalence is unknown. At least 40 affected individuals have been mentioned in the medical literature.
MEGDEL syndrome is caused by mutations in the SERAC1 gene. The function of the protein produced from this gene is not completely understood, although research suggests that it is involved in altering (remodeling) certain fats called phospholipids, particularly a phospholipid known as phosphatidylglycerol. Another phospholipid called cardiolipin is made from phosphatidylglycerol. Cardiolipin is a component of the membrane that surrounds cellular structures called mitochondria, which convert the energy from food into a form that cells can use, and is important for the proper functioning of these structures.
SERAC1 gene mutations involved in MEGDEL syndrome lead to little or no SERAC1 protein function. As a result, phosphatidylglycerol remodeling is impaired, which likely alters the composition of cardiolipin. Researchers speculate that the abnormal cardiolipin affects mitochondrial function, reducing cellular energy production and leading to the neurological and hearing problems characteristic of MEGDEL syndrome. It is unclear how SERAC1 gene mutations lead to abnormal release of 3-methylglutaconic acid in the urine, although it is thought to be related to mitochondrial dysfunction.
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
This entry is adapted from https://medlineplus.gov/genetics/condition/megdel-syndrome