This site is intended for healthcare professionals only. Designed and funded by Novartis Gene Therapies in partnership with experts.
For babies with SPINAL MUSCULAR ATROPHY (SMA)
making a fast diagnosis is vital
Refer babies by 3 months of age for urgent
review by a paediatric neurologist if you see:
For children with spinal muscular atrophy (SMA) fast diagnosis is vital. This is because any lower motor neuron damage occurring before treatment is irreversible.1,2
As a physician, you are uniquely placed to spot whether an infant is developing as they should, whether this is at a routine check up, or if parents or caregivers raise any concerns.
Watch this short video for expert insights on SMA
What is SMA?
SMA is a rare, progressive, inherited monogenic disease characterised by lower motor neuron degeneration and muscle weakness.2,3
Untreated SMA is the 2nd most common fatal autosomal recessive disorder after cystic fibrosis and the leading inherited cause of infant mortality.4,5
SMA affects 1 in 10,000 live births and can impact any race or sex6
Around 70 births are affected by SMA per year in the UK*7–9
Approximately 40 of those births are the most severe form, SMA Type 1*7–9
Approximately 1 in every
40–60 people is an SMA carrier1,6
*According to 2018 national birth statistics for England, Scotland, Wales and Northern Ireland.
Untreated SMA Type 1 is the number one genetic cause of infant death3,10
SMA Type 1
SMA is typically classified into 4 phenotypes (Types 1 to 4) that range in severity.3 In SMA Type 1, the most severe and common form, most lower motor neuron degeneration occurs in the first few months of life causing rapid and irreversible damage.2,3
Without early diagnosis and expert intervention, infants with SMA Type 1 will never achieve major motor milestones like rolling over or sitting independently.1,11
Download the SMA factsheet for more information
SMA FACTSHEET
The majority of infants with SMA Type 1 will:
Be unable to breathe or swallow unaided by age 13.5 months12
Not survive or will need permanent ventilatory support by 2 years of age12
THE SIGNS OF SMA
SMA is a rare, progressive, inherited monogenic disease characterised by lower motor neuron degeneration and muscle weakness.2,3
Head lag13,14
From lying supine, hold baby’s hands and pull gently to sitting. Head lag is present if the baby’s neck remains completely extended and lags behind their trunk. By 3 months most infants will either have no head lag or, if present, it should be minor.
Hypotonia15–17
Hypotonia (floppiness) is more prominent in the proximal muscles and affects the legs more than the arms. It can be elicited by holding the baby prone or pulling to sit.
Inability to reach11,14
Up to 3 months of age, most babies should begin to reach for toys and objects. Look out for a baby who is not reaching out for items.
If you see ANY OF these 3 signs by 3 months of age,
refer babies to a paediatric neurologist for urgent review
Other signs of SMA Type 1 might include:
Progressive, symmetrical and proximal weakness that affects the legs more than the arms and spares the facial muscles17
Difficulty with swallowing, leading to choking and aspiration17
Weak cry2
Absent or reduced reflexes14
Tongue fasciculation14
Abnormal frog-like posture (with legs splayed to the sides) when lying supine18
Unless there is a family history, diagnosis is generally prompted by the clinical signs of SMA17
Causes of SMA
SMA is caused by an absent or dysfunctional
survival motor neuron 1 (SMN1) gene.5,6
The body has a back-up gene, SMN2, however, it is only capable of producing a small amount of functional SMN protein, which is insufficient for motor neuron survival and function.19,20
Click to see the difference:
Unaffected individual
Affected individual
Unaffected individual:
SMN protein is critical for neuronal survival and neuromuscular junction formation; an SMN protein deficiency leads to irreversible neuronal loss20,21
SMN1 is the primary gene that encodes SMN protein with SMN2 as a back-up6,20
Functional SMN protein
Non-functional SMN protein
Importance of early diagnosis
Fast diagnosis is vital in SMA as any lower motor neuron damage that occurs before treatment is irreversible.1,2
Every delay in the diagnosis of SMA Type 1 can jeopardise lower motor neuron survival, directly impacting neuromuscular function2
Early signs of SMA
Early signs of SMA can be attributed to late motor development, but infants with SMA Type 1 deteriorate quickly if left untreated and by 2 years of age, most will not survive or will require permanent ventilatory support.2,12
Materials to support conversations with parents and caregivers
Parents and caregivers can be directed to www.think3at3months.co.uk for information about 3 developmental milestones in babies at 3 months.
Download our guide to support conversations with parents and caregivers
CONVERSATION GUIDE WITH PARENTS
Download our Think 3 at 3 Months poster for parents and caregivers which can be displayed in surgeries and clinics
THINK 3 AT 3 MONTHS POSTER
Referral
An infant with SMA may rely on your prompt recognition of potential SMA signs and rapid referral to a specialist neuromuscular centre.1,17
Prompt diagnosis can save lives
Diagnosis of SMA Type 1 relies on prompt recognition of the symptoms and timely genetic testing.17
Genetic testing confirms clinical diagnosis
SMN1 genetic testing is recommended first line for investigation of suspected SMA and is highly reliable.17
Immediate referral to specialist care
Following diagnosis, the SMA working group unanimously recommends immediate referral to specialist care to achieve optimal outcomes.2
Refer babies by 3 months of age to a paediatric neurologist for urgent review if you see the following signs:
PAEDIATRIC NEUROMUSCULAR CENTRES OF EXCELLENCE
Birmingham Childrens Hospital, University Hospitals Birmingham NHS Foundation Trust
Phone: 0121 424 2000
Bristol Royal Hospital for Children, University Hospitals Bristol NHS Foundation Trust
Phone: 0117 923 0000
Evelina Children’s Hospital, Guy’s and St Thomas’ NHS Foundation Trust, London
Phone: 020 7188 7188
Royal Manchester Children’s Hospital, Manchester University NHS Foundation Trust
Phone: 0161 276 1234
Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, London
Phone: 020 7405 9200
Noah’s Ark Children’s Hospital for Wales, Cardiff and Vale Health Board
Phone: 029 2074 3364
This campaign runs alongside similar initiatives with information
relevant for Allied Health Professionals and parents/caregivers.
Go to other sites:
REFERENCES
1. Govoni A, et al. Mol Neurobiol. 2018;55(8):6307–18. 2. Glascock J, et al. J Neuromusc Dis. 2018;5:145–58. 3. Farrar MA, et al. Ann Neurol. 2017;81:355–68. 4. Armstrong EP, et al. J Med Econ. 2016;19(8):822–826. 5. Lally C, et al. Orphanet Journal of Rare Diseases. 2017;12:175. 6. Mendell JR, et al. N Engl J Med. 2017;377(18):1713–22. 7. Office for National Statistics (GB). Available at: https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/livebirths. Date accessed: November 2023. 8. National records of Scotland. Available at: https://www.nrscotland.gov.uk/statistics-and-data/statistics/scotlands-facts/births-in-scotland. Date accessed: November 2023. 9. Northern Ireland Statistics and Research Agency. Available at: https://www.nisra.gov.uk/publications/registrar-generalannual-report-2016-births. Date accessed: November 2023. 10. Kolb et al. Ann Neurol. 2017;82(6):883-891. 11. De Sanctis R et al. Neuromuscul Disord. 2016;26(11):754–59. 12. Finkel RS et al. Neurology. 2014;83:810–17. 13. Markowitz JA, et al. JOGNN. 2004;33:12–20. 14. Wang CH, et al. J Child Neurol. 2007;22:1027–49. 15. Leyenaar J, et al. Paediatr Child Health. 2005;10(7):397–400. 16. Hammersmith Infant Neurological Examination (v07.07.17). 17. Mercuri E, et al. Neuromusc Disord. 2018;103–115. 18. Kolb SJ and Kissel JT, et al. Neurol Clin. 2015;33(4):831–846. 19. Verhaart IEC, et al. Orph. J Neurol. 2017;264:1465–1473. 20. Anderton RS and Mastaglia FL. Expert Rev Neurother. 2015;15(8):895–908. 21. Dimitriadi M, et al. Proc Natl Acad Sci USA. 2016;113(30):E4377–E4386. 22. Lin CW, et al. Pediatr Neurol. 2015;53:293–300.
Developed in partnership with Spinal Muscular Atrophy UK, TreatSMA, Muscular Dystrophy UK and UK experts in paediatric neuromuscular diseases
This website is intended for an audience in the UK.
© 2023 Novartis Gene Therapies. All rights reserved.
Terms of Use | Privacy and Cookies Policy | Cookie Settings
UK | NOV 2023 | 312642