Spinal muscular atrophy is a disorder wherein individuals experience breathing difficulties, limited mobility, challenges in swallowing food, muscle weakness, and delayed gross motor skills. Neurologists often diagnose this condition in childhood itself due to the manifestation of symptoms. It is a severe genetic disorder caused due to insufficient synthesis of survival motor neuron (SMN) protein. It is crucial to identify this disease in the early stage for better management. So, have a look at the different types of spinal muscle atrophy.

• SMA type 1
  The first type of the condition is also called the Werndnig-Hoffmann disease and is extremely severe among the different types of spinal muscular atrophy (SMA). It usually manifests before infants reach six months of age. In some cases, symptoms appear when the baby is barely three months old. The infants find it challenging to hold their head straight, swallow milk or semi-solid foods, have floppy arms, and cannot sit without support. The genetic disorder progresses rapidly, and babies may not live beyond two years with this condition. Doctors prescribe disease-modifying therapies (DMTs) to help them sit and show other forms of mobilities. With the advancement in technologies, now it is possible to diagnose SMA type 1 during the final months of pregnancies.
• SMA type 2
  Type 2 SMA manifests between three to 15 months of age and is also known as Dubowitz disease. It is an intermediate type of SMA as children can sit without the support of adults, but can barely walk. The limbs become more affected than the arms in the disease. Some of the patients even experience breathing difficulties, especially when they fall asleep. As the condition progresses, children may require external support to sit. The lifespan of type 2 SMA-impacted individuals is usually shorter than those with SMA type 3 or 4.
• SMA type 3
  SMA type 3 is also known as Kugelberg-Welander disease, and usually gets detected after an infant is over 18 months of age. Patients have shortened muscles and tendons, a condition known as scoliosis or contractures. It imposes restrictions on the movement of joints. Though they may face challenges in climbing up and down the stairs, affected individuals can stand or walk without any support. However, if doctors start DMTs in the early stages, the patients may lead a normal life and have a standard life expectancy.
• 4.   SMA type 4
  This genetic disorder is also known as adult SMA, as in most cases, it gets detected after a patient reaches 20 or 30 years of age. It is also the rarest among the different types of SMA. In this case, patients tend to experience breathing issues and have weak arms and legs. Since the symptoms are mild and slowly progressing, many individuals remain unaware of their health condition for several years. The life expectancy of patients also does not get impacted by this disease.

As this condition can have a huge effect on one’s daily life, it is crucial to remember that the onset of its symptoms requires medical attention at the earliest.