Glutaric aciduria type I: clinical heterogeneity and neuroradiologic features.

We present four patients, two pairs of siblings, with glutaric aciduria type I (GA I). All four had undetectable glutaryl-CoA dehydrogenase activity on fibroblast culture and massive urinary excretion of glutaric acid. All had serum carnitine deficiency at time of diagnosis except one patient who was diagnosed neonatally. All had a unique pattern of frontotemporal atrophy on CT. Remarkably, in both sibling pairs, one child was asymptomatic. This suggests that the biochemical markers hitherto identified with GA I do not encompass the entire scope of the metabolic or enzymatic abnormalities. Alternatively, as yet unidentified mechanisms might spare or delay the destructive process.