Treatments were delayed for one patient (Case 2) due to initial high maternally transferred AAV9 neutralizing antibodies (NAb) and parental concerns for nusinersen as it requires intrathecal injections; this infant received risdiplam at 71 days of life after developing areflexia and sparse tongue fasciculations, followed by SMN1 gene replacement therapy at 111 days of life when the Nab result returned negative (Table 3). This evidence concerns the gene SMN1 and Areflexia.