Abstract
We evaluated clinical and laboratory findings of the high-risk group in organic acidemias. We also evaluated those of the patients with organic acidemias diagnosed by the screening during the last three years. We did this in order to use screening facilities in an efficient way.
Twenty-four patients with 6 different organic acidemias were detected after the analysis of urinary organic acids excretion in 550 patients which constituted the high-risk group. Of the 24 patients, 20 showed acute symptoms such as vomiting, convulsion, and/or consciousness disturbance. Of these, 10 patients were diagnosed as primary lactic acidosis and the other 10 patients had secondary lactic acidosis due to propionic acidemia or methylmalonic acidemia, and so on. Two patients were suffering from glycerol kinase deficiency. The remaining two patients were diagnosed without any clinical symptoms. One had multiple carboxylase deficiency and the other had dicarboxylic aciduria.
The major reasons for screening included psychomotor retardation, convulsions, and muscular hypotonia, but the diagnostic values of those symptoms were low and calculated to be 2.5%, 3.3% and 2.9%, respectively. On the other hand, lactic acidosis, metabolic acidosis, tachypnea, and hyperammonemia were characteristic findings of organic acidemia and the diagnositic values of those findings were calculated to be 48.8%, 38.5%, 35.7% and 28.60, respectively. These results indicate that when patients with suspected organic acidemias are associated with metabolic acidosis and/or lactic acidosis during an acute illness, they may possibly be suffering from some organic acidemias.
From our three-year experience in the screening of organic acidemias, the patient with muscular dystrophy associated with psychomotor retardation are considered to be a highrisk group for glycerol kinase deficiency. Patients with hyperleucinemia detected by a neonatal screening for inborn errors of metabolism may be thought as a high risk-group for multiple carboxylase deficiency. The patients whose siblings died of Reye syndrome-like symptoms should be investigated for dicarboxylic aciduria through a urinary organic acids excretion analysis, even if there are no clinical findings.
