What is Leigh syndrome?
Leigh syndrome is a rare, inherited, degenerative disorder with many different symptoms, which usually becomes apparent in the first year of life.
It is a disease of the mitochondria, which provide energy for nerve cells in the brain and muscles.
What causes Leigh syndrome?
Leigh syndrome may be caused by a deficiency of one or several different enzymes. These enzyme deficiencies are caused by mutations in one of several disease genes.
There is some evidence that these mutations may be inherited as an autosomal recessive trait, an X-linked recessive trait, or as a mutation found within the DNA of mitochondria. Rarely, no genetic cause of Leigh syndrome can be identified.
What are the symptoms of Leigh syndrome?
Symptoms of classical Leigh syndrome usually start in children between the ages of 3 months and two years. The first noticeable symptoms in early onset cases (e.g. 3 months) include poor sucking ability and lack of head control. There may also be a lack of appetite, vomiting, irritability, crying and possible seizures.
If the onset is later in childhood (e.g. 3 years old) a child may struggle articulating words, coordinating movements and previously acquired intellectual skills may diminish.
Progressive neurological deterioration with Leigh syndrome is marked by general weakness, clumsiness, spasms, lack of muscle and lack of reflexes.
Many children with Leigh syndrome will develop respiratory issues. There is also the risk of visual problems such as sluggish pupils, paralysis of certain eye muscles and visual impairments which may result in blindness.
Leigh syndrome may also affect the heart. Some children have abnormal enlargement of the heart, and excess growth of the fibrous membrane that divides the various chambers of the heart.