Leigh syndrome is a severe neurological disorder that usually becomes apparent in the first year of life. This condition is characterized by progressive loss of mental and movement abilities (psychomotor regression) and typically results in death within two to three years, usually due to respiratory failure. A small number of individuals do not develop symptoms until adulthood or have symptoms that worsen more slowly.

Leigh syndrome can be caused by variants (also called mutations) in one of more than 110 different genes. In humans, most genes are found in DNA in the cell's nucleus, called nuclear DNA. However, some genes are found in DNA in specialized structures in the cell called mitochondria. This type of DNA is known as mitochondrial DNA (mtDNA). While most people with Leigh syndrome have a variant in nuclear DNA, about 20 percent have a variant in mtDNA.

Leigh syndrome affects at least 1 in 40,000 newborns. The condition is more common in certain populations. For example, the condition occurs in approximately 1 in 2,000 newborns in the Saguenay Lac-Saint-Jean region of Quebec, Canada and in approximately 1 in 1,700 individuals on the Faroe Islands.

Leigh syndrome can have different inheritance patterns. It is most commonly inherited in an autosomal recessive pattern, which means both copies of the gene in each cell must have a variant to cause the disorder. This pattern of inheritance applies to most of the Leigh syndrome-associated genes contained in nuclear DNA, including SURF1. The parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but they typically do not show signs and symptoms of the condition.

Published Date: April 28, 2023
Published By: National Institutes of Health