New Academic Article Reviews Treatment Results in Patients who were Diagnosed with SMA Through Newborn Screening
A new academic article, co-authored by Alliance Chair Laurent Servais, has been published. Laurent and his colleagues undertook a systematic review of treatment results in patients who were diagnosed with SMA through newborn screening.
Whilst previous clinical trials have clearly demonstrated the efficacy of presymptomatic treatment, the prognosis of patients diagnosed with SMA through newborn screening could not be inferred through those trials as, in some cases, disease presents very early and symptomatic patients were excluded from these trials.
The article acknowledges that classification based on symptom onset and SMA Type is not appropriate for patients identified through newborn screening. However, given the correlation between SMA phenotype and the number of copies of SMN2, this is an important factor to assess when reviewing treatment results for patients identified through newborn screening. For patients with no symptoms, SMN2 copy number may provide an indication of when a patient will develop the first manifestations of the disease and what milestones will be achieved in the absence of treatment.
This review provides evidence that patients with three SMN2 copies and no symptoms present with an excellent functional prognosis. At the other end of the spectrum, patients with two copies and symptoms at treatment initiation are very likely to present with motor delay and ambulation cannot be guaranteed.
This review of treatment results for patients who were diagnosed with SMA through newborn screening found that:
• Of 35 patients with three SMN2 copies, treated before 42 days of age, and followed-up for at least 18 months, all but one achieved autonomous ambulation.
• Of 41 patients with two SMN2 copies, who were non-symptomatic at treatment initiation, all achieved a sitting position independently, and 31 were able to walk.
• Of 16 patients with two SMN2 copies, followed-up for at least 18 months who presented with symptoms at onset, 3 achieved the walking milestone and all but one were able to sit without support.
This review therefore demonstrates that the results of early treatment depend on the number of SMN2 copies and the initial neurological status of the patient.
The full article is available to read here >