LEBERS CONGENITAL AMAUROSIS ASSOCIATED WITH MITOCHONDRIAL DYSFUNCTION

We report the case histories of two 6-month-old girls, both with young , nonconsanguineous parents, referred to us for suspected blindness. I n both cases, Leber's congenital amaurosis was diagnosed. Due to persi stently high lactic acid levels in blood, muscle biopsies were taken. Analysis of biopsies revealed that both patients had low levels of com plex IV of the mitochondrial respiratory chain; one patient additional ly had low levels of complex III. Microscopic and ultra-structural alt erations of muscle, typically observed in mitochondrial disorders, wer e observed only in the second patient. These observations raise the po ssibility that at least some cases of Leber's congenital amaurosis may be due to alterations in the mitochondrial respiratory chain.