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Spinal Muscular Atrophy (SMA) is a progressive neuromuscular disease affecting approximately 1 in 10,000 births worldwide and 1 in 6,000 births in Turkey. The disease is divided into four main types based on the age of onset and severity. Type 1 and Type 2 are the most commonly observed forms of SMA.
Type 1 (Severe) SMA: Also known as Werdnig-Hoffmann Disease, Type 1 SMA is the most severe and most frequently encountered form of the disease. It typically manifests at birth or within the first 6 months of life. Symptoms include pronounced hypotonia (floppiness) in the legs, poor trunk control, and severely restricted mobility. Infants with Type 1 SMA usually cannot sit independently and experience difficulties with feeding, swallowing, head control, and breathing. The disease progresses rapidly, leading to muscle weakness and recurrent respiratory infections.
Type 2 (Intermediate) SMA: Type 2 SMA, which has a milder course than Type 1, typically presents with symptoms in infants aged 7 to 18 months. These children generally cannot stand or walk independently but may be able to crawl. The rate of disease progression can vary significantly among individuals. Type 2 SMA usually affects the legs more than the arms, and additional symptoms such as tremors in the hands, scoliosis, general weakness, and difficulty gaining weight may be observed. Respiratory infections are also common. Life expectancy can range from early childhood to adulthood, depending on the severity of the patient's condition.
Type 3 (Mild) SMA: Also known as Kugelberg-Welander Disease or Juvenile Spinal Muscular Atrophy, Type 3 SMA symptoms begin after 18 months of age and sometimes may not be noticed until adolescence. These patients initially show normal development, being able to stand and walk, but may struggle to rise from a sitting position. Over time, mobility restrictions may increase, and the use of a wheelchair might become necessary. Patients with Type 3 SMA are also at risk for respiratory infections.
Type 4 (Adult) SMA: The rarest type of SMA, Type 4, exhibits symptoms in adulthood. In this form, disease progression is slow, and patients can generally maintain their independent motor skills throughout life. Other complications are rarely observed in Type 4 SMA.
It is important to consult a doctor immediately if you notice any of the above-mentioned symptoms in your child or yourself.
What are the Types of SMA Disease?
Type 1 (Severe) SMA: Also known as Werdnig-Hoffmann Disease, Type 1 SMA is the most severe and most frequently encountered form of the disease. It typically manifests at birth or within the first 6 months of life. Symptoms include pronounced hypotonia (floppiness) in the legs, poor trunk control, and severely restricted mobility. Infants with Type 1 SMA usually cannot sit independently and experience difficulties with feeding, swallowing, head control, and breathing. The disease progresses rapidly, leading to muscle weakness and recurrent respiratory infections.
Type 2 (Intermediate) SMA: Type 2 SMA, which has a milder course than Type 1, typically presents with symptoms in infants aged 7 to 18 months. These children generally cannot stand or walk independently but may be able to crawl. The rate of disease progression can vary significantly among individuals. Type 2 SMA usually affects the legs more than the arms, and additional symptoms such as tremors in the hands, scoliosis, general weakness, and difficulty gaining weight may be observed. Respiratory infections are also common. Life expectancy can range from early childhood to adulthood, depending on the severity of the patient's condition.
Type 3 (Mild) SMA: Also known as Kugelberg-Welander Disease or Juvenile Spinal Muscular Atrophy, Type 3 SMA symptoms begin after 18 months of age and sometimes may not be noticed until adolescence. These patients initially show normal development, being able to stand and walk, but may struggle to rise from a sitting position. Over time, mobility restrictions may increase, and the use of a wheelchair might become necessary. Patients with Type 3 SMA are also at risk for respiratory infections.
Type 4 (Adult) SMA: The rarest type of SMA, Type 4, exhibits symptoms in adulthood. In this form, disease progression is slow, and patients can generally maintain their independent motor skills throughout life. Other complications are rarely observed in Type 4 SMA.
It is important to consult a doctor immediately if you notice any of the above-mentioned symptoms in your child or yourself.