Lack of Awareness, Screening Slows SMA Diagnosis in Infants

Of the 4 most common forms of SMA, the 3 that most affect patients are usually diagnosed before the age of 3 years. In Type I SMA, the most severe and common of these 4, irreversible denervation can begin as early as 3 months. Patients with this type of SMA typically require invasive supportive care as symptoms progress and lose approximately 90% of motor units by 6 months of age. They are generally unable to sit on their own before the treatment. But recent literature has shown that these babies are not diagnosed until an average age of 6.3 months, after most of the damage has already been done, the study authors note.

The symptoms of Type I SMA begin on average after about 2.5 months, meaning there are likely to be missed cases that could have benefited from earlier intervention. Although newborn screening for SMA is recommended in the United States, only about 68% of newborns are screened for it, the authors noted. But that’s not the only barrier.

“Given the complexity of the interface between pediatric and specialist care, including supply shortages, busy neurologists’ schedules, and the lack of adequate health insurance, there may be interference in the delivery of effective care coordination and referral,” they wrote.

To measure awareness and awareness of SMA, developmental screening and referral patterns, Cure SMA conducted 2 historical surveys among pediatricians in 2018 and 2019.

The 2018 survey focused on physician awareness, diagnostic requirements, and use of screening tools. The 2019 survey gathered more detailed information on practices, implementation of development screening tools, and barriers to specialist referrals. Together, they wanted to assess pediatricians’ comfort level identifying signs of neuromuscular disease (NMD) and predict whether they would immediately refer a baby to a pediatric neurologist if an infant or toddler showed early signs of SMA.

A total of 21,264 pediatricians were contacted for the 2018 survey and 19,096 were contacted for the 2020 survey. The first received 300 completed responses and the second received 600 (overall response rates of 2.3% and 4.5%), respectively. Both studies were completed by a subset of 42 physicians.

In the 2018 survey, 52.7% of respondents correctly identified genetic testing as a requirement for a definitive diagnosis of SMA, while 31% incorrectly selected muscle biopsy as a requirement. In the 2019 survey, an even lower percentage (45%) answered correctly.

Current guidelines recommend the use of screening tools at well visits, although 56% of physicians who responded to the 2018 survey reported screening at each well visit. In 2019, 37.3% of respondents reported using screening tools across all source visits. In 2019, researchers looked for links between the use of screening tools and physician demographics, finding that those who completed their education less than 10 years prior to the survey were 1.55 times more likely to use screening tools at each source visit. or at 9-, 18-, and 30-months compared to pediatricians with more than 10 years of experience.

When it came to identifying early signs of NMD, 70.3% of respondents said they felt comfortable, with 3.3% answering ‘extremely comfortable’, 18.7% ‘moderately comfortable’ and 48. .3% ‘comfortable’. Those who were moderately or extremely comfortable were 1.47 times more likely to immediately refer a patient to a pediatric neurologist for evaluation. Overall, 67.3% of the respondents said they were familiar with SMA, but 59.4% of that subgroup correctly identified the genetic testing requirement for diagnosis.

In terms of referrals, average wait times were between 1-6 months for specialist visits, with most between 1-2 months, according to 64.2% of respondents. When ranking barriers to referral, the top 3 were insurance coverage, lack of triage at specialty offices, and lack of neurologist or pediatric neurologist in the region.

Overall, the review found that newborn screening, early symptom recognition, and prompt referral in symptom identification remain areas where physicians can improve.

“Despite the advent of genetic screening, a definitive tool for the diagnosis of SMA, improved education and awareness efforts regarding early symptoms, and 3 new FDA-approved disease-modifying treatments,” the authors concluded, “the findings of these 2 studies point to that the clinical knowledge gaps among pediatricians across different industries and experience levels, and point to potentially modifiable factors contributing to the delay in SMA diagnosis.”


Curry M, Cruz R, Belter L, Schroth M, Lenz M, Jarecki J. Consciousness screening and referral patterns in United States pediatricians regarding early clinical features of spinal muscular atrophy (SMA). BMC Pediatrician. Published online May 17, 2021. doi:10.1186/s12887-021-02692-2

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