MEGDEL syndrome
General description
MEGDEL syndrome is an inherited metabolic disorder characterized by four key features: 3-methylglutaconic aciduria (MEG), dystonia with deafness (D), encephalopathy (E), and a Leigh-like presentation (L). The syndrome is associated with abnormally high levels of 3-methylglutaconic acid and 3-methylglutaric acid in the urine, which are diagnostic markers for this condition. Due to overlapping clinical and biochemical characteristics, patients are often initially diagnosed with Leigh syndrome, especially when brain MRI reveals abnormal basal ganglia signals.
The condition is caused by mutations in the SERAC1 gene. In addition to the core symptoms, liver involvement has been identified in some cases, leading to the expanded term "MEGDHEL syndrome" to account for hepatic impairment as a fifth characteristic.
Putaminal eye sign
-
Putamen
The putaminal lesions generally affect the anterior and posterior portion, while sparing the mid portion, a pattern known as the putaminal eye sign.
Caudate nuclei and globus pallidi
-
Caudate nucleus
-
Globus pallidus
MRI shows bilateral T2WI and FLAIR hyperintensity in the basal ganglia, with the globus pallidi typically involved from the early stages of the disease.
Cerebellar atrophy
-
Cerebellum
The cerebellum commonly exhibits progressive atrophy, evidenced by an abnormally broadened fourth ventricle.