A NEW PATIENT WITH ALPHA-KETOGLUTARIC ACIDURIA AND PROGRESSIVE EXTRAPYRAMIDAL TRACT DISEASE

A 4.5-year-old boy with chronic progressive encephalopathy is describe d. The clinical presentation initially included seizures and hypotonia which later evolved into severe extrapyramidal disease and dementia. The gas chromatography/mass spectrometry (GC/MS) analysis of urine ind icated that alpha-ketoglutarate was increased 210 times and aconitic a cid 80 times. No disturbance of acid/base balance, lactic acid or ammo nia metabolism accompanied this clinical picture. The fibroblasts cont ained 29% of normal alpha-ketoglutarate dehydrogenase activity, while the activity of another mitochondrial marker enzyme, glutamate dehydro genase, was normal. The neuroimaging studies revealed bilateral striat al necrosis. The clinical and biochemical findings were almost identic al to two previously reported patients. Experience with this patient e mphasizes the need for detailed organic acid biochemical investigation in any progressive encephalopathy and that extrapyramidal tract signs should evoke the possibility of alpha-ketoglutaric aciduria, among ot her 'neurologic organic acidemias'.