Children axonal dystrophy (Infantile axonal dystrophy) - Gen PLA2G6.
Neuroaxonal dystrophy child is a disorder that primarily affects the nervous system. People with children axonal dystrophy often have no symptoms at birth, but between 6 and 18 months old begin to present delays in acquiring new motor and intellectual skills, such as crawling or start talking. In addition, these individuals have developmental regression. In some cases, signs and symptoms of the disease first appear later in childhood or adolescence and progress more slowly.
Affected children have progressive movement difficulties. Generally they have hypotonia and later gradually, spasticity. Eventually, these children lose the ability to move independently. In addition, lack of muscle strength causes difficulty with feeding. This muscle weakness may also lead to problems that can cause frequent respiratory infections, such as pneumonia. Other signs and symptoms of the disease include nystagmus, strabismus, optic nerve atrophy, hearing loss and dementia. Over time, these individuals lose awareness of their entorno.En some individuals, abnormal levels of iron accumulate in the basal ganglia.
This disease is due to mutations in the gene PLA2G6, located on the long arm of chromosome 22 (22q13.1). This gene encodes a type of enzyme called phospholipase A2. This enzyme is involved in the metabolism of phospholipids, important for many body processes, such as keeping the cell membrane intact and working properly. Specifically, phospholipase A2, sometimes called PLA2 group VI, it helps regulate the concentrations of a compound called phosphatidylcholine, which is abundant in the cell membrane.
They have identified at least 50 mutations in the gene in people with PLA2G6 child axonal dystrophy. Mutations in the gene damage the function of the enzyme PLA2 group VI, which can alter the maintenance of cell membrane and contribute to the development of the spheroidal bodies on nerve axons. Although it is not known how the problems of phospholipid metabolism are associated with the main function of this enzyme, both neuroaxonal dystrophy as child in a similar condition called pantothenate kinase associated neurodegeneration. These alterations, as well as Alzheimer's disease and Parkinson's disease, also associated with changes in brain iron metabolism. It is unclear how iron buildup that occurs in some people with children axonal dystrophy can contribute to the characteristics of this disorder. Some people with children axonal dystrophy have mutations in the gene PLA2G6. The genetic cause of the disease in these cases is unknown.
This disease is inherited in an autosomal recessive pattern, that is, both copies of the gene in every cell must have mutations for alteration is expressed. The parents of an individual with an autosomal recessive disease have a copy of the mutated gene, but usually show no signs and symptoms of the disease.
Tests in IVAMI: in IVAMI perform detection of mutations associated with infantile neuroaxonal dystrophy, by complete PCR amplification of the exons of the gene PLA2G6, and subsequent sequencing.
Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).