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Spinal Muscular Atrophy (SMA) Treatment in Hyderabad: 1 in 38 Indians Is a Carrier — The Earlier the Diagnosis, the More the Treatment Can Do
Expert SMA diagnosis, nusinersen and risdiplam access guidance, respiratory support, and genetic counselling at KIMS Neuroscience, Secunderabad, Hyderabad.
About This Condition
Key Facts About Spinal Muscular Atrophy in India
The genetic basis, India-specific epidemiology, the diagnostic delay problem, and the access reality — at a glance.
What it is
A genetic condition caused by mutations in the SMN1 gene, leading to progressive loss of the motor neurons in the spinal cord that control voluntary muscle movement. The result is progressive muscle weakness and wasting — from severe and life-threatening in infancy to mild and adult-onset, depending on the type.
The genetic cause
Mutations (most commonly deletions) in the SMN1 (Survival Motor Neuron 1) gene on chromosome 5q. Autosomal recessive — both parents must be carriers for a child to be affected. The SMN2 gene acts as a partial backup — the number of SMN2 copies modifies disease severity.
How common in India
Incidence 1–2 per 100,000 population in India. Carrier rate 1 in 38 in India — meaning approximately one in every 38 Indians carries one mutated copy of SMN1 without being affected themselves. SMA molecular testing is the third most common genetic test performed in India after beta-thalassemia and DMD testing.
The diagnostic delay problem
Most SMA diagnoses in India are made only after age 2 — by which time significant and irreversible motor neuron loss has already occurred in Type 1 and Type 2 patients. This delay is the single greatest obstacle to achieving the best possible outcomes from disease-modifying therapy.
The treatment revolution
SMA has three established, globally approved disease-modifying therapies: nusinersen (Spinraza, intrathecal injection), risdiplam (Evrysdi, daily oral liquid), and onasemnogene abeparvovec (Zolgensma, one-time gene therapy for children under 2). All three have robust clinical trial evidence and slow or halt motor neuron loss. Access within India differs for each (see below), but their efficacy and global approval status is well established. The earlier treatment begins, the greater the benefit — ideally before significant weakness has developed.
India access reality
Risdiplam (Evrysdi) is the only SMA disease-modifying therapy commercially marketed in India as of 2025. A bottle costs approximately Rs 6.2 lakh; annual cost for a patient weighing over 20kg is at least Rs 60 lakh at discounted government rates. The National Policy for Rare Diseases provides a maximum of Rs 50 lakh — insufficient for continued treatment. KIMS supports families through access programmes and legal pathways.
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The Condition Where Time Is Motor Neurons
A 6-month-old girl in Hyderabad has never lifted her head during tummy time. Her parents assumed she was a slow developer. At 8 months she cannot sit unsupported. She startles normally, her eyes follow movement, and she smiles and interacts — her cognition is entirely intact. But she has no head control and her legs barely move. Her cry has become softer. Her breathing, on close observation, is paradoxical — the chest draws in while the belly pushes out, indicating diaphragm-driven breathing because the chest muscles are too weak to contribute.
The paediatrician orders a serum CK — it is normal. A child with severe muscle weakness and a normal CK is not a myopathy. At KIMS Neuroscience, the referral letter describing this picture triggers an immediate SMN1 genetic test. The result: homozygous deletion of exon 7 of the SMN1 gene. Two copies. Confirmed SMA Type 1.
Spinal Muscular Atrophy is the most common fatal genetic disease in infants. Before 2016 — before the first disease-modifying therapy was approved — SMA Type 1 was a uniformly devastating diagnosis: children lost the ability to swallow, then breathe, and most died before age 2. Today, the prognosis has been transformed. Children who receive disease-modifying therapy early — ideally before symptoms are severe, ideally in the presymptomatic phase — can achieve motor milestones they would never have reached untreated. Some are walking.
The critical phrase is: early. Spinal Muscular Atrophy kills motor neurons. Once a motor neuron is lost, it cannot be replaced. The disease-modifying therapies slow or stop the loss of further neurons — they cannot restore neurons already gone. Every week of diagnostic delay in a SMA Type 1 infant is motor neurons that will never come back. This is why the 1-in-38 carrier rate in India, the 3rd-most-common-genetic-test status, and the devastating reality that most Indian SMA diagnoses are made after age 2 — are not just statistics. They are the clinical case for urgency.
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040-44885000Emergency line: 040-46324365What SMA Does — The SMN Protein and the Motor Neuron
The SMN1 gene produces SMN (Survival Motor Neuron) protein, which is essential for the maintenance and function of motor neurons — the nerve cells in the anterior horn of the spinal cord that send signals down peripheral nerves to drive every voluntary muscle movement: breathing, swallowing, walking, reaching, and speaking.
When both copies of SMN1 are deleted or mutated (as in all standard SMA), SMN protein production falls drastically. Without adequate SMN, motor neurons progressively degenerate and die. The muscles they innervated lose their signal and atrophy. The weakness is progressive, irreversible, and follows a proximal-to-distal pattern — the muscles closest to the trunk are most severely affected, while the hands and feet may be relatively preserved even in advanced disease.
A second gene — SMN2 — is a near-identical copy of SMN1 that produces a small amount of functional SMN protein (approximately 10–15% of a normal level) because most of its mRNA undergoes aberrant splicing that excludes exon 7. The number of SMN2 copies varies between individuals and is the primary determinant of disease severity: more SMN2 copies = more functional protein = less severe disease. SMA Type 1 patients typically have 1–2 SMN2 copies; Type 2 patients typically have 3; Type 3 and 4 patients typically have 3–4 or more.
Why SMN2 copy number matters for treatment decisions
All three disease-modifying therapies work by increasing SMN protein production — either by modifying SMN2 splicing to include exon 7 (nusinersen, risdiplam), or by delivering a functional SMN1 gene directly (onasemnogene abeparvovec). Patients with more SMN2 copies have more substrate for the SMN2-targeting therapies to work with, and tend to show greater functional improvement. The SMN2 copy number is therefore reported alongside the SMN1 deletion result at KIMS and is used to guide treatment planning and realistic outcome expectation-setting with families.
The SMA Types — A Spectrum from Lethal in Infancy to Mild in Adulthood
SMA is classified into five types based on the age of onset and the highest motor milestone achieved before disease progression. The same genetic cause — SMN1 deletion — produces this wide spectrum, with SMN2 copy number and other modifiers determining which type a patient has.
Type 0
Prenatal / birth
None — severe hypotonia at birth
Death within weeks to months. Severe arthrogryposis, respiratory failure from birth. Extremely rare.
Type 1 (Werdnig-Hoffmann)
Birth to 6 months
Never sits independently
Without treatment: death before age 2 from respiratory failure in most. With early DMT: dramatically improved — some achieve sitting and walking with presymptomatic treatment.
Type 2
7–18 months
Sits, never walks
Survives into adulthood with respiratory support. Progressive scoliosis, respiratory decline. With DMT: stabilisation and improvement in motor function documented in real-world studies.
Type 3 (Kugelberg-Welander)
After 18 months
Walks independently
Near-normal life expectancy. Gradual proximal weakness. Some lose walking in adulthood. With DMT: slowing of progression well documented.
Type 4
Adulthood (>21y)
Walks — mild weakness only
Normal life expectancy. Mildest form. Proximal limb weakness without significant respiratory involvement in most.
How SMA Presents in India — Recognising It Sooner
In India, SMA is recognised later than it should be — for several interconnected reasons. Understanding these patterns is essential for the referring physicians, paediatricians, and families who interact with KIMS before a formal specialist assessment.
The Floppy Infant — The Most Common Entry Point
SMA Type 1 presents as a “floppy baby” — a term that describes global hypotonia (reduced muscle tone) in an infant who otherwise has normal alertness and social engagement. The specific pattern that distinguishes SMA from other causes of floppy infant syndrome:
Profound proximal weakness with relative preservation of distal movement — the baby may move the fingers and feet but cannot lift the arms or legs against gravity
Paradoxical breathing — the chest moves inward while the abdomen moves outward on inspiration (bell-shaped chest), indicating intercostal muscle weakness with preserved diaphragm function
Absent or very reduced deep tendon reflexes
Fasciculations of the tongue — small, rapid, worm-like movements of the tongue surface visible on careful inspection. This sign is virtually pathognomonic of SMA
Normal CK — unlike muscular dystrophies, SMA produces a normal or minimally elevated CK because the problem is in the motor neuron, not the muscle itself
Alert, responsive infant with normal cognition and vision — SMA does not affect the brain
The CK clue that is frequently missed in India
In a floppy infant, a normal serum CK is strongly suggestive of a motor neuron or neuromuscular junction disorder rather than a primary myopathy or muscular dystrophy. Many Indian paediatricians interpret a normal CK as reassuring and defer further workup. At KIMS, a normal CK in a floppy infant is not reassuring — it immediately elevates SMA on the differential diagnosis and triggers SMN1 genetic testing.
The Child Who Sits But Cannot Walk — SMA Type 2
SMA Type 2 presents between 7 and 18 months with a child who achieves sitting but fails to pull to stand or walk. The characteristic features: a fine tremor of the outstretched hands (minipolymyoclonus), absent knee jerks, progressive scoliosis, and a waddling or absent gait. This child is often attributed to rickets, vitamin D deficiency, or developmental delay. A serum CK is ordered, found normal, and the workup stops. SMN1 genetic testing is rarely considered in this scenario without specialist input. At KIMS, a child who sits but does not walk by 18 months with absent reflexes and a normal CK receives SMN1 testing on the day of assessment.
The Teenager or Adult With Proximal Weakness — SMA Type 3 and 4
SMA Type 3 (Kugelberg-Welander disease) presents in childhood to early adulthood with slowly progressive proximal limb weakness. The child can walk but has difficulty climbing stairs, running, and rising from the floor. This pattern is frequently attributed to Limb-Girdle Muscular Dystrophy — and indeed the two conditions can look clinically identical. The distinguishing features at KIMS: absent reflexes (more consistent in SMA than many LGMDs), normal or near-normal CK in SMA Type 3 vs elevated CK in LGMD, and the EMG showing neurogenic rather than myopathic pattern. SMA Type 4 presents in adulthood and may be entirely asymptomatic until later life, often picked up through family genetic testing.
Diagnosis at KIMS
Diagnosis at KIMS
A coordinated, day-of-assessment diagnostic pathway — combining genetic testing, neurophysiology, respiratory and swallowing assessment, and family carrier testing — to confirm SMA, characterise its severity, and accelerate treatment planning.
SMN1 genetic testing — the definitive first test
MLPA (multiplex ligation-dependent probe amplification) of the SMN1 gene detects homozygous deletion of exon 7 in approximately 95% of SMA cases. This is a blood test available at KIMS. Result time: typically 2–4 weeks. In the rare cases where MLPA does not detect a deletion (approximately 5% of SMA patients have one deletion and one point mutation), full SMN1 sequencing is performed. SMN2 copy number is reported simultaneously — this is essential for treatment planning. At KIMS, genetic testing for SMA is initiated at the first specialist appointment without waiting for EMG or further workup in any case where the clinical suspicion is strong.
EMG and nerve conduction studies
EMG in SMA shows a neurogenic pattern: large, polyphasic motor unit potentials on voluntary contraction (indicating motor neuron loss with compensatory reinnervation of surviving fibres), with spontaneous activity (fibrillations and positive sharp waves) indicating ongoing active denervation. Nerve conduction studies are typically normal in early SMA. The EMG pattern distinguishes SMA from myopathic conditions and from peripheral neuropathies.
Respiratory assessment
Forced vital capacity (FVC) by spirometry in cooperative children over 5 years, or overnight oximetry and polysomnography in younger children unable to perform spirometry. The respiratory baseline determines urgency of treatment initiation and timing of non-invasive ventilation. In SMA Type 1, respiratory assessment may reveal life-threatening compromise at the time of diagnosis.
Swallowing and nutritional assessment
Videofluoroscopy swallow study in SMA Type 1 and Type 2 patients with bulbar involvement. Nutritional assessment and dietitian review — poor weight gain and malnutrition compound respiratory and motor deterioration in SMA. Gastrostomy planning in SMA Type 1 patients with progressive bulbar weakness.
Carrier testing of parents and at-risk family members
Once SMA is confirmed in a child, both parents are offered SMN1 carrier testing. In the context of India’s 1-in-38 carrier rate, siblings, aunts, and uncles of the affected child also have elevated carrier risk and may benefit from testing before planning their own pregnancies. At KIMS, cascade carrier testing and genetic counselling are arranged for the wider family as part of the diagnosis disclosure process.
Treatment
Disease-Modifying Therapies — What They Are, How They Work, and the India Access Reality
SMA has three established, globally approved disease-modifying therapies (DMTs) that have transformed its prognosis: nusinersen, risdiplam, and onasemnogene abeparvovec. All three target the root cause — insufficient SMN protein — through different mechanisms, and all three have FDA and international regulatory approval with robust clinical trial evidence. At KIMS, all three are discussed with families at the time of diagnosis, with honest and specific information about what is accessible in India.
Comparison of the Three Therapies
Nusinersen (Spinraza)
Antisense oligonucleotide — modifies SMN2 pre-mRNA splicing to include exon 7, increasing functional SMN protein production
Intrathecal injection (lumbar puncture). Loading: 4 doses over 2 months. Maintenance: every 4 months lifelong
All ages, all types
Not commercially marketed in India. Individual import / named patient access only. Rs 92 lakh per injection.
Indian cohort study (n=25): median HFMSE improvement of 3.5 points over follow-up
Risdiplam (Evrysdi)
Small molecule — oral SMN2 splicing modifier. Same mechanism as nusinersen but taken as daily oral liquid syrup
Oral liquid, once daily, lifelong
All ages, all types (from 2 months)
Only SMA DMT commercially marketed in India. Rs 6.2 lakh per bottle. Annual cost Rs 60+ lakh for >20kg patients.
Indian cohort study (n=11): median HFMSE improvement of 2.5 points over follow-up
Onasemnogene (Zolgensma)
AAV9 gene therapy — delivers a functional SMN1 gene directly into motor neurons via a single intravenous infusion
Single intravenous infusion. One-time only
Children under 2 years for standard use (weight <21kg)
Not commercially available in India. One-time global cost approximately Rs 16 crore. Compassionate access extremely limited.
Indian cohort study (n=9): median HFMSE improvement of 4 points — highest of the three in this study
What KIMS does to help
The Indian government's National Policy for Rare Diseases provides a maximum of Rs 50 lakh in financial assistance — insufficient for continued risdiplam treatment in most patients. In October 2024, the Delhi High Court issued a landmark ruling (Master Arnesh Shaw v Union of India) ordering the government and pharmaceutical companies to improve access for SMA and other rare disease patients, though the Supreme Court subsequently stayed this judgment pending further proceedings. At KIMS, we assist families through:
Risdiplam access at government-negotiated pricing through CDSCO-approved channels
Applications to manufacturer patient assistance programmes (Roche’s Evrysdi patient support)
Connection with SMA patient organisations including Cure SMA India and DART for peer support and funding navigation
Honest prognostic counselling to help families prioritise limited resources
Respiratory and rehabilitation optimisation as the foundation of care regardless of DMT access
Supportive Care at KIMS — The Foundation Regardless of DMT Access
Whether or not a family can access disease-modifying therapy, comprehensive supportive management significantly extends life expectancy and quality of life in SMA. At KIMS, this is structured and systematic.
Respiratory Management
Respiratory failure is the leading cause of death in SMA Type 1 and Type 2. A proactive respiratory programme — surveillance, assisted ventilation, secretion clearance, vaccination, and advance care planning — is the cornerstone of long-term survival.
Overnight oximetry and sleep study — baseline and then every 6 months in SMA Types 1 and 2
Non-invasive ventilation (BiPAP) started when overnight oximetry shows desaturation, or when FVC falls below 50% predicted — significantly extends survival in SMA Type 2 and non-ambulant Type 3
Mechanical insufflator-exsufflator (cough assist device) — essential for managing chest infections without hospitalisation in SMA patients who cannot generate effective cough. Available for KIMS outpatients through loan equipment programme
Chest physiotherapy protocol — taught to carers at KIMS for home daily use
Pneumococcal and annual influenza vaccination — respiratory infections are the leading cause of acute deterioration and hospitalisation in SMA in India
Early intubation decision planning — KIMS initiates advance care planning discussions with SMA Type 1 families at diagnosis, covering non-invasive ventilation vs long-term tracheostomy vs comfort-focused care, according to the family’s values and wishes
Nutritional and Swallowing Support
Dietitian review at diagnosis — adequate nutrition is essential for muscle function and immune competence; malnutrition compounds weakness
Modified food textures and thickened fluids for pharyngeal weakness in SMA Type 1 and Type 2
Gastrostomy (PEG) tube placement in SMA Type 1 patients with progressive swallowing difficulty — eliminates aspiration risk from feeding and ensures adequate caloric intake. Planned proactively at KIMS rather than in crisis
Physiotherapy and Orthotics
Daily passive range-of-motion exercises — to prevent joint contractures in all SMA types
Hydrotherapy — exercise in warm water reduces the gravitational challenge on weak muscles and allows movements not possible on land
Spinal monitoring — scoliosis develops rapidly in non-ambulant SMA patients. Annual spinal X-ray, with early referral for spinal bracing and surgical correction planning
Ankle-foot orthoses, hand splints, and specialised seating systems — prescribed and reviewed at each KIMS visit
Genetic Counselling and Reproductive Planning
At KIMS, genetic counselling for SMA families covers inheritance, cascade carrier testing, prenatal diagnosis, pre-implantation options, and the case for newborn screening.
Autosomal recessive inheritance explained — both parents are carriers; 25% recurrence risk per pregnancy
Carrier testing for siblings of both parents — in the context of India’s 1-in-38 carrier rate, extended family testing is strongly recommended
Prenatal diagnosis options — chorionic villus sampling (CVS) at 11–13 weeks for SMN1 deletion testing of the fetus
Pre-implantation genetic diagnosis (PGD) via IVF — testing embryos before implantation to select unaffected embryos
Newborn screening discussion — the case for newborn SMN1 screening before symptoms develop, which would allow presymptomatic treatment initiation. India does not yet have a national SMA newborn screening programme; KIMS advocates for its introduction
Related Conditions
Spinal Muscular Atrophy belongs to the family of neuromuscular disorders affecting the motor neuron, nerve, neuromuscular junction, or muscle:
FAQs
Frequently Asked Questions
1 in 38 Indians is a carrier for SMA. If two carriers have a child, there is a 1-in-4 chance that child will have Spinal Muscular Atrophy. Most Indian SMA children are diagnosed after irreversible damage has occurred. The earlier the diagnosis, the more the treatment can do.
At KIMS Neuroscience, Secunderabad, Hyderabad, every SMA family receives the complete assessment on the day of first consultation: SMN1 and SMN2 genetic testing initiated, respiratory function measured, swallowing assessed, and disease-modifying therapy access planning begun. We support families through the Indian access landscape for risdiplam honestly and practically — including patient support programme applications, government funding pathways, and connection with patient organisations. We do not leave families to navigate this alone.
International enquiries: info@kimsneurosciences.com