August is Spinal Muscular Atrophy (SMA) Awareness Month. Organizations like Cure SMA work diligently to educate the public about this genetically passed disease that is the leading cause of death of infants up to 2 years of age. 1 in 50 Americans, despite gender or race, can be a carrier of this recessive gene. Being informed and spreading knowledge on the probability, risks, and effects of this disease is helpful in family planning and the pursuit of finding a cure.
SMA is caused by a mutation of the survival motor neuron gene 1 (SMN1) that is responsible for muscle development necessary to walk, eat, and/or breathe. This recessive (non-dominant) gene affects nerves with the spinal cord that is responsible for producing the protein necessary for normal muscle growth. When the SMN1 gene is mutated, it hinders muscle development and causes the nerves within the muscles to die. Since SMA only affects physical development, it is hard to recognize if a newborn has this disease until they do not meet the typical developmental milestones.
There are five types of SMA. Each type is based on the age of the individual affected, the onset of muscular atrophy (lose), and the highest milestone achieved. Type 0 is exceedingly rare and very severe, with symptoms beginning prior to birth and is seen as decreased fetal movement in the weeks prior to delivery. Type I, also known as Werdnig-Hoffman disease, is typically diagnosed within the first 6 months of a child’s life. This is the most severe form of SMA. It is also the most common form of SMA, accounting for 60% of all SMA cases. When these babies’ muscle development is debilitated, they suffer from the inability to swallow or breathe due to respiratory failure, which may lead to death. Type II SMA is usually diagnosed after 6 months of age, but before two years of age. Children who suffer from this form of SMA are only slightly impaired. Those affected can sit up on their own, but do not meet the developmental milestones for motor (walking) skills. This causes them to need a wheelchair. SMA Type III is diagnosed after the child is 18 months old and up to 3 years old. These individuals may meet the typical milestones for walking but will lose this ability over time. This also can require them to use a wheelchair. The rarest form of SMA is Type IV. This type will not affect the person until they are 35 years old (some cases as early as 18 years old). Type IV SMA results in only mild motor impairment.
One way of treating SMA is to increase the amount of survival motor neuron protein in the body. These ways of treating SMA are often called “SMN-based” or “SMN-enhancing” approaches. Many SMN-enhancing treatments target this SMN2 gene, causing it to make more useable SMN protein. Other SMN-enhancing approaches work to replace or repair the mutatedSMN1gene directly. For example, on December 23, 2016, the Federal Drug Administration (FDA) approved a treatment, available to all ages and types of SMA, called SPINRAZA (Nusinersen). The first approved therapy for those who have this genetic mutation! To learn more about this treatment option please visit Cure SMA. If you would like to learn more about SMA overall, please visit Cure SMA Advocates. Let’s continue to bring awareness to SMA to the public in hopes of continuous breakthroughs in treatments and healthy babies.
If you have questions regarding any of the information mentioned in this week’s article, please do not hesitate to call my Capitol or District Office. Please always feel free to contact my office if you have any questions or issues regarding a Texas state agency, or if you would like to contact my office regarding constituent services. As always, my offices are available at any time to assist with questions, concerns, or comments (Capitol Office, 512-463-0672; District Office, 361-949-4603).
– State Representative Todd Hunter, District 32
Rep. Hunter represents Aransas County and Nueces County (Part). He can be contacted at firstname.lastname@example.org or at 512-463-0672.