spinal muscular atrophy (SMA)

**Spinal Muscular Atrophy** (SMA) is a progressive genetic disorder that affects the control of muscle movements. This disease is caused by dysfunction of the nerves that control voluntary movements. He has tested SMA on hundreds of samples... The largest number of SMA patients reported in the Middle East has been published by him in a prestigious journal of scientific reports... Also, an experiment has been conducted to check the highest sensitivity in this laboratory for diagnosing SMA in time... Iran... Types of spinal muscular atrophy This disease is divided into four groups according to the age of onset of symptoms and the severity of the disease: ### Spinal muscular atrophy type I Werding-Hoffman disease: This type of SMA is the most severe type of the disease.. Symptoms are present at birth or appear in the first six months after birth.. In affected infants, growth delay is seen with severe hypotonia and lack of spontaneous movements.. These children have normal mental ability... and finally the child dies in the first two years of life... #S## This type of disease is milder than type I and the most common type of SMA. It is characterized by muscle weakness between the ages of 6 and 18 months. These children can sit without help, but they do not have the ability to move or stand independently. The two main problems of children with type II are respiratory infections due to weakness of the muscles of the respiratory system, curvature of the spine (scoliosis) and hump (kyphosis) due to weakness of the muscles of the spine. Muscular atrophy Spinal cord type III Kugelberg-Velander disease: It is a milder type of this disease that appears after 18 months.... All patients are able to walk... but the weakness and laxity of the muscles, especially the leg muscles, when walking and going up and down the stairs is quite evident at the age of two to three years... (scoliosis) is present.... The life expectancy of these people is normal.... Type IV atrophy The onset of this type of disease is in the second decade and often in the third decade of life.. Affected individuals usually show mild to moderate muscle weakness.. This type of disease has characteristics similar to type III.. The SMN1 and SMN2 genes are involved in the production of a protein called survival motor neuron protein and are located on the high duplication chromosome and are relatively large in several DNA features.. The number of false genes... Mutations in the SMN1 gene cause spinal muscular atrophy type I, II, III or Without SMN protein, motor neurons are destroyed and nerve impulses are not transmitted between the brain and muscles. As a result, some muscles are unable to function or move normally. In approximately 94% of patients with this disease, the deletion of both versions of exon 7 of the SMN1 gene occurs. be: - The affected person has muscle relaxation with inability to perform spontaneous movements.... - ECG shows fibrillation and muscle denervation... - Serum creatine kinase may be normal or increased.... - Even if the above symptoms are present, the diagnosis is confirmed only when it is confirmed by genetic tests... diagnosis of SMA disease **Diagnosis of the disease** SMA in the first stage with clinical examinations by a specialist doctor, performing physical tests, taking a nerve and muscle tape (EMG) and also studying family records.... For the final diagnosis of this disease, genetic testing is done with molecular methods... Prenatal diagnosis of SMA disease In addition to families who have had a child with SMA, nowadays for couples who have been identified as carriers after carrying out a genetic test, there is a possibility of **prenatal diagnosis** of SMA.... For this purpose, in the early months of pregnancy, placental villi are sampled from the fetus at 10 to 12 weeks with CVS or at 14 to 14 weeks.. Genetics This disease is inherited with an autosomal recessive pattern... that is, every repeated gene in every cell is mutated in the patient.... People who have one copy of the defective gene are carriers of the disease and do not have signs and symptoms of the disease and show a healthy phenotype.. At-risk relatives and prenatal testing for at-risk pregnancies... Determining the status of the SMA carrier can be done with molecular genetic tests in the family members of the affected person. - Checking the number of copies of exon 7 of the SMN1 gene with a precise Real Time PCR method... - Checking the number of copies of exon 7 and 8 of the SMN1 and SMN2 genes using a precise method... - A high precision SMA carrier test Is SMA disease curable? No, there is no drug for **definitive treatment** of SMA.... Based on the type of disease and clinical symptoms, there are drugs to control and slow down the progression of the disease, which are among the most expensive drugs in the world... Disease control drugs These drugs prevent the progression of the disease by helping to make the SMN protein.... Nosinersen drug under the brand name Spinraza is prescribed for children aged two to twelve years old.... This drug is injected into the spinal canal.... Rizdiplam drug is administered orally from two months to adulthood... Gene therapy Onasemenogen Abeparovec, brand name Zolgensema, is administered intravenously only once to children under two years of age. This drug replaces the healthy version of the SMN1 gene with a defective one. How common is SMA? Approximately one out of every six thousand babies is born with SMA disease and one out of forty people is a carrier of this disease... What does it mean to be a carrier of SMA disease? Each of us has two copies of each gene, one from the father and the other from the mother... SMA carriers inherit one healthy and one defective copy of the SMN1 gene. **Life expectancy** of SMA varies based on the type and age of onset.. Babies with type 1 usually die before the age of two, but children with type 2 may live into early adulthood and sometimes longer depending on the severity of the disease.. People with types 3 and 4 live like healthy people... One of my relatives has SMA... yes.... Spinal muscular atrophy is a hereditary disease.... If you have someone in your family, there is a possibility that you are a carrier of this disease.... What is the genetic screening test for SMA? In general, genetic screening tests check the chance of having a defective gene related to known genetic diseases. By doing this test before pregnancy or during pregnancy, the possibility of your child having genetic diseases is checked. How is the SMA disease screening test done? **SMA screening test** is done on a blood sample....one parent is usually tested first....if the test results show that the parent is a carrier, the other parent is tested... How are the results of the SMA screening test interpreted? The results of the screening test are reported as the number of normal copies of the SMN1 gene: if you have two or more healthy copies of the SMN1 gene, the probability of carrying SMA is very low.. If you have one healthy copy of the SMN1 gene, it means that the second copy is defective and although you are a carrier for SMA testing.. they are not 100%.. Currently, screening for SMA carriers is based on the number of copies of the SMN1 gene.. Approximately 5% of the population has more than A copy of They have the SMN1 gene in one chromosome and there is no copy of it in the other chromosome.. Such a situation is called a silent carrier.. In the case of a silent carrier, the probability of passing the defective version to the next generation in each pregnancy is 50%.. Considering the high costs of treatment and the high frequency of transmission of this disease in Iran, this test is recommended to all women who decide to become pregnant or are in early pregnancy... When is the best time to perform the SMA screening test Is it? This test can be done before pregnancy and early pregnancy... It is recommended to do it before pregnancy because you have enough time... For more information, refer to the Pars Genome page... Also, if you wish, you can contact Pars Genome in person or online.