GLUT1 deficiency syndrome ... (GLUT1 deficiency syndrome) - Gen SLC2A1
The GLUT1 deficiency syndrome is a process that affects the nervous system and can have a variety of neurological signs and symptoms. This process is classified into two types depending on the characteristics and associated clinical manifestations: common GLUT1 deficiency and GLUT1 deficiency syndrome not epilepticus.
Approximately 90% of those affected have type commonly called GLUT1 deficiency syndrome. These people have epilepsy from the first months of life. In newborns, the manifestation of irregular , rapid involuntary movements of the eyes, is the first sign of the disease. Newborns with common GLUT1 deficiency syndrome have normal head size at birth but often the growth of brain and skull is slow, which can lead to microcephaly. In addition, people with this syndrome may have developmental delay, mental retardation, spasticity, ataxia, dysarthria, episodes of confusion, lethargy, headaches and myoclonus, particularly in periods of fasting.
Approximately 10% of individuals with GLUT1 deficiency syndrome is a form of the condition known as GLUT1 deficiency syndrome not epilepticus, which is usually less severe than the common form. People with non - epileptic seizures have no way but may have developmental delay, mental retardation, ataxia or dystonia, and movement problems that may be more pronounced than in the common form.
There are several changes that originally received other denominations and considered variants of GLUT1 deficiency syndrome. These alterations include paroxysmal choreoathetosis the spasticity (dystonia 9), dyskinesia paroxysmal exercise induced and epilepsy (dystonia 18) and certain types of epilepsy. Rarely, people with variations of the GLUT1 deficiency syndrome have abnormal red blood cells and anemia.
Both common type as the type of non - epileptic syndrome are due to mutations in both the SLC2A1 gene (solute carrier family 2 glucose -facilitated Transporter- member 1), located on the short arm of chromosome 1 (1p34.2). This gene encodes the glucose transporter protein type 1 (GLUT1). This protein is part of the cell membrane, where glucose from the blood into the cells to be used as an energy source. It is involved in glucose transport through the blood brain barrier between capillaries of nerve tissue. Also transports glucose between glial cells that protect and maintain the nerve cells.
There are more than 150 mutations in the SLC2A1 gene in people with GLUT1 deficiency syndrome. Mutations in the gene SLC2A1 reduce or eliminate the function of the protein GLUT1. Accordingly, the amount of glucose available to brain cells is reduced, thus affecting the development and function of the brain.
This disease is usually inherited as an autosomal dominant, which means that a copy of the altered gene in each cell is sufficient for alteration is expressed. About 90% of cases of GLUT1 deficiency syndrome are caused by new mutations in the gene and occur in people with no history of disease in your family. In other cases, an affected person inherits the mutation from an affected parent. In a small number of families, syndrome GLUT1 deficiency is inherited as an autosomal recessive pattern, which means that 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 GLUT1 deficiency syndrome, by complete PCR amplification of exons SLC2A1 gene, 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).