Spinal Muscular Atrophy (SMA) is a common cause of death for children in India leading to about one in 7,744 children dying. If not diagnosed or left untreated, the child does not survive beyond two years of age.
Delay in screening stemming from limited laboratories that are capable of diagnosing genetic diseases and abysmally low public awareness are the primary reasons for the progression of the disease to an early fatal outcomes. Parents can sometimes delay in getting proper treatment after the disease is detected, by seeking a second, third or fourth medical opinion. Hence, there is a need to raise awareness among the patients, their families and the general public.
The parents of babies with SMA need to promptly seek care from specialists like paediatricians and neurologists to recognize the disease early and start treatment.
Let's understand SMA
Our body has a type of nerve cells, also called motor neurons, in the brain stem and spinal cord. They control our skeletal muscle activity such as walking, speaking, swallowing, and breathing and the movement in the legs, chest, face, arms, throat, and tongue. When suffering from SMA – a group of hereditary diseases, these motor neurons get destroyed.
When there are disruptions in the signals between motor neurons and muscles, the muscles begin wasting, gradually weaken the muscles and develop fasciculation or twitching.
Genes control all our body functions. Some of the genes enable the body to produce various proteins in the right amount. Survival motor neuron (SMN) is one of the critical proteins in our body.
SMA is caused by a mutation in the SMN1 gene that leads to decreased levels of SMN. SMA is inherited in an autosomal recessive way which means the affected individual has defective genes, inherited from both parents. Autosomal recessive diseases can affect more than one child in the same family – siblings or cousins.
There are several impairments in SMA which are caused by defects in the survival motor neuron 1 (SMN1) gene that range from difficulty in breathing at birth to mild muscular weakness in adults.
This SMA is classified into four types: SMA type 1 or Werdnig-Hoffmann disease or infantile-onset SMA; SMA type 2 or the intermediate form; SMA type 3 or Kugelberg-Welander disease and SMA type 4.
In Type 1, due to a defective gene, the cells do not produce enough SMN. The symptoms of this type are present at birth or appear by the age of six months and the babies generally have a weak cry, difficulty in breathing, weakness of muscles, difficulty in swallowing, and the bay cannot sit unassisted. These infants have two or three copies of the SMN2 gene.
In Type 2, babies between the ages of three to 15 months have three copies of the SMN2 gene. This makes their muscles close to the centre of the body week and usually, the muscles of the face and the eyes remain unaffected. Such patients may also suffer from respiratory and breathing problems.
In Type 3, babies develop symptoms after 18 months of age. Some signs may not be visible until later in childhood. These patients experience difficulty in climbing stairs and may lose the ability to stand and walk as they grow older. Most of them develop scoliosis, foot deformities, and respiratory muscle weakness.
In Type 4, infants have eight copies of the SMN2 gene. The age of this type usually occurs after the age of 30. This is the mildest form of SMA; therefore the individual may live a normal life.
Managing SMA with advanced treatment options
Until 2016, SMA was considered incurable due to a lack of treatment options. However, we now have many treatment options that can improve the quality of life of patients with SMA. There are three approved treatments globally for SMA — Spinraza (Nusinersen), Evrysdi (Risdiplam), and Zolgensma (Onasemnogene aboparvovec).
In India, these treatments are provided as a part of humanitarian access programs.
Spinraza (Nusinersen) is a treatment used for all four types of SMA. It is a disease-modifying treatment option for which there are significant clinical trial data available stating after three months of therapy, it can improve motor skills. The treatment entails treatment every four months followed by life-long maintenance doses.
Zolgensma (Onasemnogene, abeparvovec) is given to SMA patients under the age of two with bi-allelic mutations in the survival motor neuron 1 (SMN1) gene. It is an adeno-associated virus vector-based gene therapy wherein there is a one-time intravenous infusion of the dosage.
Evrysdi (Risdiplam) is for two-month or older children. It is a survival motor neuron-2 (SMN2) splicing modifier for SMA. Through daily dosing, Evrysdi treats peripheral tissues and increases functional levels of the SMN protein throughout the central nervous system. It is administered daily by mouth in liquid form at home or by feeding tube. Evrysdi increases the production of the SMN protein which is responsible for transmitting signals from the brain to the muscles to move. There is evidence that it increases the levels of SMN protein and provides significant improvement in patients with different types of SMA.
Making treatments affordable with right policies
Today, when advanced treatment options are available to save patients with SMA, there are certain barriers including lack of awareness that have impacted patients over the years. Zolgensma gene therapy is available at an exorbitant price making it out of reach of families of SMA patients. To address this, in India, there are online platforms such as ImpactGuru and Milaap that help families to raise funds for the treatment.
In July 2021, the government finalised the National Policy for Rare Diseases (NPRD) in which voluntary crowdfunding for the treatment of rare diseases like SMA was approved. As per the policy, a digital platform would be created to bring hospitals together where SMA patients are being treated. And prospective individuals or corporate donors willing to support such patients can donate. The government is also encouraging PSUs and corporate houses to support it under the Corporate Social Responsibility Rules of Companies Act.
In India, parents are often helpless due to the high out-of-the-pocket expenditure for the treatment of SMA. Effective implementation of policies like NPRD will help these families get financial help. However, to ensure quality treatments reach patients, there is a dire need to spread awareness. Early diagnosis and timely treatment can help to save thousands of babies who succumb to this disease each year. This will help children achieve motor milestones like being able to roll onto their side, ability to stand and sit without support, swallow, and many other functions to survive and achieve their full potential of physical and psychosocial development.
The author is the Chair of the Indian Academy of Public Health, Indian Alliance of Patients Groups
from Firstpost India Latest News https://ift.tt/3plZujn
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