An 43-month-old female baby, born in February 2021, got MLPA examination after birth because of the family history of SMA, and the results showed SMN1 gene exon 7, 8 homozygous deletions and two copies of SMN2 gene. The baby was admitted to the Department of Neurology of Shenzhen Children's Hospital for the first time in March 2021.Physical examination showed she had normal muscle strength and tone and good motor function, and therefore she was diagnosed with presymptomatic 5q SMA. Nusinersen intrathecal injection was given to the baby after all preparations were completed. She was subsequently multiple readmitted for the treatment and motor function assessment according to the medication plan. Up to now, the child has received a total of 14 treatments without interruption. And she was additionally treated with Risdiplam by her parents in January 2024. From the beginning until now, her breathing and eating functions have been normal, without scoliosis. Her motor development milestone is slightly delayed compared to normal children: head up stability and head up 90 degrees in prone position at 4-month, flip from supine position to prone position at 6-month, sit with hand support at 8-monthand sit alone at 9-month, walk by holding her one hand at 13-month, walk alone at 16-month, walk steadily at 19-month, play alone on a slide at 30-month, jump with both feet at 36-month, and her motor function score is lower than that of normal children. Currently, her various life skills and motor function performances are roughly similar to those of normal children of the same age.