Leigh disease is an extremely rare disorder.

In the case of Leigh disease, crucial cells in the brain stem and basal ganglia are affected.

Pathological similarities between Leigh disease and WE led to the hypothesis that the cause was a defect in thiamine metabolism.

Leigh disease: Clinical and pathological symptoms usually appear in the first year of life and include psychomotor retardation and brain stem dysfunction.

The latter account for the majority of Leigh disease, although it is not always possible to identify the specific mutation responsible for the condition in a particular individual.

The neurological features of Leigh disease caused by PDHC deficiency are indistinguishable from other forms.

Leigh disease (subacute necrotising encephalomyelopathy) is an inherited disorder that affects mostly infants in the first years of life and is invariably fatal.

Leigh disease, also known as Subacute Necrotizing Encephalomyelopathy (SNEM), is a rare neurometabolic disorder that affects the central nervous system.

Leigh disease can also be caused by deficiency of the pyruvate dehydrogenase complex (PDHC), most commonly involving a PDHC subunit which is encoded by an X-linked gene (OMIM 308930).

Other differential diagnoses include metabolic disorders (such as GM2 gangliosidosis, phenylketonuria, hypothyroidism, Leigh disease) primarily dystonic juvenile parkinsonism, autosomal recessive early onset parkinsonism with diurnal fluctuation, early onset idiopathic parkinsonism, focal dystonias, dystonia musculorum deformans and dyspeptic dystonia with hiatal hernia.

Mutations in this gene have been associated with Leigh syndrome.

A subset of patients also suffer from Leigh syndrome.

This has a bearing upon choice of therapy and allows a much more exact prognosis than a characterization simply as, say, Leigh syndrome.

Disorders of movement in Leigh syndrome.

Mutations in the subunits of complex I can cause mitochondrial diseases, including Leigh syndrome.

Leigh syndrome is a neurodegenerative disorder that has been linked to a defect in an enzymatic formylation reaction.

Leigh syndrome is typically associated with defects in oxidative phosphorylation, which occurs in the mitochondria.

Bi-allelic mutations (i.e. both copies of the gene are mutated) have been described in Leigh syndrome.

SdhA mutations can lead to Leigh syndrome, mitochondrial encephalopathy, and optic atrophy.

A primary defect in oxidative phosphorylation defines class I. Distinct mitochondrial pathologies may overlap more than one class, for example Leigh syndrome (see below).

Disorders involving dysfunctional COX assembly via gene mutations include Leigh syndrome, cardiomyopathy, leukodystrophy, anemia, and sensorineural deafness.

When this mutation is present in a higher percentage of a person's mitochondria-greater than 90 percent to 95 percent-it causes a more severe condition known as maternally inherited Leigh syndrome.

An integrative genomics strategy led to the discovery that mutations in LRPPRC cause the French-Canadian variant of Leigh syndrome.

Exome sequencing, has been used to identify a mutation in the gene coding for mitochondrial methionyl-tRNA formyltransferase (MTFMT) in patients with Leigh syndrome.

Mutations giving rise to Leigh syndrome have also been described in the flavoprotein subunit (Fp or SDHA) of the succinate dehydrogenase complex (SDH) [ 20, 21].

As already described for LHON, Leigh syndrome and HSP, the causative mutations are not necessarily confined to a single protein-coding gene, or even to the nuclear versus the mitochondrial genome.

Mutations found in at least two nuclear genes also correlate with Leigh syndrome: one for a subunit of the pyruvate dehydrogenase complex and one for surfeit locus protein 1 (SURF-1), which is involved in the assembly of cytochrome c oxidase.

His team findings also include rare disease mutations such as the genes for spastic ataxia of Charlevoix-Saguenay (ARSACS) and Leigh syndrome French-Canadian Type (also known as lactic acidosis), that affect many families from the Saguenay region, of which he is a native.

Leigh syndrome Leigh syndrome (also known as subacute necrotizing encephalomyelopathy) is another common mtDNA mutation disorder, frequently associated with cytochrome oxidase (COX) deficiency [ 13], though no disease-related mutations of the mtDNA-encoded COX subunits have been reported.

Leigh disease, also known as Subacute Necrotizing Encephalomyelopathy (SNEM), is a rare neurometabolic disorder that affects the central nervous system.

The third form of COX deficiency, known as Leigh's disease (subacute necrotizing encephalomyelopathy), is thought to be a generalized (systemic) form of COX deficiency.

Leigh syndrome Leigh syndrome (also known as subacute necrotizing encephalomyelopathy) is another common mtDNA mutation disorder, frequently associated with cytochrome oxidase (COX) deficiency [ 13], though no disease-related mutations of the mtDNA-encoded COX subunits have been reported.