Pediatric muscle weakness disease or Spinal Muscular Atrophy (SMA) is a genetic disorder that severely affects the nervous system and muscles, causing muscle weakness and muscle wasting. It hinders growth and makes daily life difficult. Gene Therapy, an innovative gene therapy for treating pediatric muscle weakness, is therefore a treatment option that can help children have a better quality of life.
What is pediatric muscle weakness disease (SMA)
Pediatric muscle weakness disease (Spinal Muscular Atrophy – SMA) is caused by an autosomal recessive genetic abnormality (Autosomal Recessive) that leads to progressive degeneration of lower motor neurons (Anterior Horn Cell) in the spinal cord. The cause is a mutation in the SMN1 (Survival Motor Neuron 1) gene located on autosomal chromosome pair 5, resulting in reduced production of SMN protein and loss of control over muscles throughout the body. This is especially critical in children during the first 2 years of life, in whom severe symptoms carry a risk of death from this disease. Receiving treatment before symptoms appear or by the age of 6 weeks is very important. The incidence is 1 in 6,000 to 10,000 live births, and the carrier frequency is 1 in 40 – 60
What are the symptoms of pediatric muscle weakness disease (SMA)
Symptoms of pediatric muscle weakness disease (SMA) are classified by age and severity into 4 types as follows:
- Spinal muscular atrophy type 0 (SMA type 0) Severe pediatric muscle weakness from birth Rare; respiratory failure often occurs, leading to death within a short period.
- Spinal muscular atrophy type 1 (SMA type 1) Severe pediatric muscle weakness The most common type. Symptoms begin between 2 – 6 months of age. Muscle wasting, delayed gross motor development, inability to sit up or hold the head up, hypotonia, progressively worsening weakness, and breathing problems. Decreased or absent reflex responses. Requires ventilatory support; without a ventilator, death may occur within 2 years.
- Spinal muscular atrophy type 2 (SMA type 2) Moderate pediatric muscle weakness Symptoms begin between 6 – 18 months of age. Muscle wasting; can sit upright but cannot walk; has swallowing problems and abnormal breathing; may often have tremor at the fingertips.
- Spinal muscular atrophy type 3 (SMA type 3) Mild pediatric muscle weakness Symptoms begin from 18 months – 2 years of age. Can walk but with abnormal gait; progressive weakness may eventually lead to inability to walk, but no breathing problems; life expectancy is normal.
How is pediatric muscle weakness disease (SMA) diagnosed
- Detailed history taking
- Physical examination, electrodiagnostic testing, muscle enzyme testing
- Genetic testing to identify abnormalities in the SMN1 gene
How is pediatric muscle weakness disease (SMA) treated
Pediatric muscle weakness disease (SMA) cannot be completely cured. Pediatricians select treatment primarily based on severity and the child’s age. Main treatment methods include:
- Medications to increase production of SMN protein in the body, administered via lumbar puncture (intrathecal injection)
- Gene Therapy Gene therapy treatment is a gene-replacement therapy given as an intravenous injection. It was approved by the U.S. Food and Drug Administration (US FDA Approval) in 2019 and by the Thai Food and Drug Administration, Ministry of Public Health, in 2023.
- Supportive care such as ventilators, bracing/casting, physical therapy, etc.
What is (Gene Therapy) gene therapy treatment
Gene therapy treatment (Gene Therapy) is an innovative medication approach that replaces the defective gene from the early stage of the disease, using a virus as a vector to deliver the SMN1 gene to lower motor neurons to treat pediatric spinal muscular atrophy. It is administered as a single intravenous injection and is carried out in accredited medical facilities by specifically trained personnel.
Preparation before treatment with (Gene Therapy) gene therapy
- Liver function test
- Kidney function test
- Immune level test
- Platelet test (Complete Blood Count)
- Troponin level test (Troponin-I) for cardiac screening
Side effects of (Gene Therapy)gene therapy treatment
- Increased liver enzyme levels
- Thrombocytopenia (low platelet count)
- Increased cardiac enzyme level troponin (Troponin-I)
Advantages of (Gene Therapy)gene therapy treatment
- Children who do not yet have symptoms: if treated with gene therapy, they will be able to sit and walk.
- Children who have symptoms: if treated with gene therapy, their motor function development will improve.
- Infants with SMA type 1 : early treatment helps increase survival rates and improves quality of life.
How to prevent pediatric muscle weakness disease (SMA)
Carrier screening for genetic diseases in couples is very important because pediatric muscle weakness disease (SMA) is inherited in an autosomal recessive pattern. If both the father and mother are carriers of the abnormal gene—meaning they carry the mutation but are not affected—then the child has a 25% chance of having pediatric muscle weakness disease (SMA) and a 50% chance of being a carrier like the parents. Carrier screening for genetic diseases before planning a pregnancy is very important.
Treating pediatric muscle weakness disease (SMA) with gene therapy treatment (Gene Therapy) as a one-time treatment from the early stage of the disease is highly effective in the long term and provides more clearly effective outcomes than other methods. However, it must be provided under close, holistic care by experienced pediatricians and in a hospital with modern equipment and an experienced multidisciplinary team.
Which hospital is good for treating pediatric muscle weakness disease (SMA)
Pediatric Center, Bangkok Hospital is ready to provide care and treatment for pediatric muscle weakness disease (SMA) with the expertise of specialized pediatricians, nursing teams, multidisciplinary professionals, and modern treatment technology so that your little one can grow up with quality in the future.
Physicians specialized in treating pediatric muscle weakness disease (SMA)
- Dr. Thianchai Bunnalai Pediatrician, Pediatric Center, Bangkok Hospital
- Dr. Suchawadee Horsuwan Pediatrician, Neurology Pediatric Center Bangkok Hospital
