A genetic disorder that causes Leigh’s disease can be inherited in three different ways. It may be inherited on the X (female) chromosome as a genetic deficiency of an enzyme called pyruvate dehydrogenase complex (PDH-Elx). It could also be inherited as an autosomal recessive condition that affects the assembly of an enzyme called cytochrome-c-oxidase (COX). And finally, it may be inherited as a mutation in the DNA in the cell mitochondria.
Leigh’s Disease Symptoms
The symptoms of Leigh’s disease usually begin between the ages of 3 months and 2 years. Since the disease affects the central nervous system, symptoms may include:
Poor sucking abilityDifficulty holding up the headLosing motor skills the infant had such as grasping a rattle and shaking itLoss of appetiteVomitingIrritabilityContinuous cryingSeizures
As Leigh’s disease becomes worse over time, the symptoms may include:
Generalized weaknessLack of muscle tone (hypotonia)Episodes of lactic acidosis (accumulation of lactic acid in the body and brain) that may impair breathing and kidney functionHeart problems
Diagnosis
Diagnosis of Leigh’s disease is based on specific symptoms. Tests may show a deficiency of pyruvate dehydrogenase or the presence of lactic acidosis. Individuals with Leigh’s disease may have symmetrical patches of damage in the brain that may be discovered by a brain scan. In some individuals, genetic testing may be able to identify the presence of a genetic mutation.
Treatment
Treatment of Leigh’s disease usually includes vitamins such as thiamine (vitamin B1). Other treatments may focus on the symptoms present, such as anti-seizure drugs or heart or kidney medicines.
Physical, occupational, and speech therapy can help a child reach his or her developmental potential.
