Leukoencephalopathy deficient RNase T2 (T2-deficient RNAse leukoencephalopathy) - Gen RNASET2
Leukoencephalopathy deficient RNase T2, also known as cystic leukoencephalopathy in RNASET2 poor is a disease that affects the brain. Affected individuals suffer from neurological problems, usually nonprogressive, which become evident during childhood. Most affected individuals manifest severe mental retardation, spasticity and delayed development of motor skills. Some individuals fail to walk, and most do not develop the ability to speak. Other neurological signs that may be present in these individuals include sensorineural hearing loss, convulsions, athetosis, dystonia and nystagmus.
In addition to neurological problems associated with leukoencephalopathy deficient RNase T2, some people affected have unusual facial features sometimes described as "doll face". Neurological problems in this disease are due to abnormalities in the brain. Leukoencephalopathy in people with deficient RNase T2, myelin is not produced in sufficient quantities during development, causing brain damage. In addition, affected individuals may have cysts in the temporal lobes and enlarged ventricles near the center of the brain. Lesions of the white matter is mainly concentrated around the cysts and ventricles. Moreover, it is frequent microcephaly.
This process is due to localized in RNASET2 gene (ribonuclease T2), located on the long arm of chromosome 6 (6q27), encoding the ribonuclease T2 (RNase T2), a protein that is abundant in the brain mutations. Ribonucleases help break RNA. Studies suggest that the ribonuclease T2 may also be involved in other functions within the cells, to regulate angiogenesis and help prevent the growth of cancerous tumors.
They have identified at least 10 gene mutations in people with RNASET2 leukoencephalopathy deficient T2 RNase. The mutations described so far result in loss of protein function ribonuclease T2. It is not known how the loss of this protein causes brain abnormalities and characteristic neurological disease problems. It has been observed that the signs and symptoms of deficiency leukoencephalopathy with RNase T2 are similar to those caused by cytomegalovirus (CMV), when a fetus is transmitted during pregnancy. Efforts are under way to understand how viral infection, or the body's response to it, and the loss of function of ribonuclease T2 could have similar effects on the developing brain. It is believed that both may be related to changes in angiogenesis or immune response to RNA that has not been broken properly.
This disease is inherited in 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 leukoencephalopathy deficient RNase T2, by complete PCR amplification of exons RNASET2 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).