Patient description: The patient is a 14-year-old boy complaining of scoliosis and back pain. He has no other medical condition. He used to be able to play routine activities such as basketball and soccer, however, he recently has problem doing them. The pain is in his leg and back and aggravated by physical activities. He prefer lying down most of the time. He is not happy with his body gesture and complaints of shoulder imbalance and shifting his head to right. Patient is a well-dressed and well-nourished adolescent who is alert and cooperative. The left shoulder is slightly higher than the right shoulder. The scoliotic curve is measured as 45 degree. The patients is candidate for scoliosis surgery according to perioperative MEP monitoring

Clinical trial eligibility criteria: eligible ages (years): 0.5-60.0,  Spinal Muscular Atrophy Confirmed diagnosis of 5q-autosomal recessive SMA Previous enrollment in Study BP29420 (Moonfish) with the splicing modifier RO6885247 or previous treatment with any of the following: 1.) Nusinersen (defined as having received >= 4 doses of nusinersen, provided that the last dose was received >= 90 days prior to screening) or 2.) Olesoxime (provided that the last dose was received <= 12 months and >= 90 days prior to screening) or 3.) AVXS-101 (provided that the time of treatment was >= 12 months prior to screening) Adequately recovered from any acute illness at the time of screening and considered well enough to participate in the opinion of the Investigator For women of childbearing potential: negative blood pregnancy test at screening, agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures, and agreement to refrain from donating eggs for at least 28 days after the final dose of study drug For men: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures and agreement to refrain from donating sperm For participants aged 2 years or younger at screening: 1.) Parent or caregiver of participant is willing to consider nasogastric, naso-jejunal or gastrostomy tube placement, as recommended by the Investigator, during the study to maintain safe hydration, nutrition and treatment delivery; 2.) Parent or caregiver of participant is willing to consider the use of non-invasive ventilation, as recommended by the Investigator during the study  Inability to meet study requirements Concomitant participation in any investigational drug or device study With the exception of studies of olesoxime, AVXS-101, or nusinersen: Previous participation in any investigational drug or device study within 90 days prior to screening, or 5 half-lives of the drug, whichever is longer Any history of gene or cell therapy, with the exception of AVXS-101 Unstable gastrointestinal, renal, hepatic, endocrine, or cardiovascular system diseases as considered to be clinically significant by the Investigator Inadequate venous or capillary blood access for the study procedures, in the opinion of the Investigator For patients aged < 2 years, hospitalization for a pulmonary event within 2 months prior to screening and pulmonary function not fully recovered at the time of screening Lactating women Suspicion of regular consumption of drugs of abuse For adults and adolescents only, positive urine test for drugs of abuse or alcohol at screening or Day -1 visit