Lactic acidosis with necrotizing encephalopathy in two sibs

Abstract

Two brothers are described who presented during the second year of life with ataxia, muscle twitching, and intermittent hyperpnoea at rest. The condition progressed, with mental deterioration, loss of scalp hair, and death after about 6 months. One child had widespread, symmetrical, degenerative lesions of the brain and spinal cord resembling those previously described in infants with 'necrotizing encephalopathy'. The histological lesions in the second child were similar, but not so marked, nor so widespread. The intermittent hyperpnoea of one child, and possibly of both, resulted from spontaneous increases of lactic acid in the blood. The erythrocytes were able to form lactic acid by glycolysis at a rate faster than those of two normal subjects. It is suggested that the proportion of phosphorylated hexoses to free glucose in the blood may have been raised, thus partly accounting for the increased glycolytic rate. There was also a renal aminoaciduria and a lowered serum phosphate concentration. This is believed to be the first description of familial lactic acidosis in young children.