Transient neonatal polyuria and renal failure: New features of MEGDEL syndrome

Background and objectives: MEGDEL (3-methylglutaconic aciduria with deafness, encephalopathy, and Leigh-like) syndrome is a mitochondrial disorder recently associated with recessive mutations in SERAC1. Our objective was to describe new clinical features of MEGDEL syndrome. Case report : This 6 year-old girl was the first child of consanguineous Turkish parents. She exhibited an acute neonatal deterioration with severe lactic acidosis and hepatic cytolysis. Initial evaluation revealed massive polyuria and renal failure with 3-methylglutaconic aciduria. Symptoms and biological findings progressively improved with symptomatic treatment but lactic acidosis and high lactate to pyruvate ratio along with 3-methylglutaconic aciduria persisted. At 8 months of age, a subacute neurological regression occurred with severe hypotonia, dystonia with extrapyramidal movements and failure to thrive. Brain MRI revealed necrotizing lesions in basal ganglia suggestive of a Leigh syndrome. At 2 years of age, sensorineural deafness was documented. MEGDEL syndrome was suspected and sequencing analysis of SERAC1 identified an already reported homozygous mutation. Discussion and conclusion: neonatal polyuria and renal failure have not been reported to date in SERAC1 defective patients. Such neonatal kidney findings expand the clinical spectrum of MEGDEL syndrome.