Wen-Chin Weng1,2, Yu-Kan Hsu1, Fu-Man Chang3, Chun-Yen Lin4, Wuh-Liang Hwu1,2,5, Wang-Tso Lee1,2, Ni-Chung Lee1,2,5, Yin-Hsiu Chien6,7,8. 1. Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan. 2. Department of Pediatrics, National Taiwan University College of Medicine, Taipei, Taiwan. 3. Department of Pediatrics, Taitung MacKay Memorial Hospital, Taitung, Taiwan. 4. Department of Pediatrics, Taipei City Hospital Renai Branch, Taipei, Taiwan. 5. Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan. 6. Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan. chienyh@ntu.edu.tw. 7. Department of Pediatrics, National Taiwan University College of Medicine, Taipei, Taiwan. chienyh@ntu.edu.tw. 8. Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan. chienyh@ntu.edu.tw.
Abstract
PURPOSE: Early identification and treatment of spinal muscular atrophy (SMA) are crucial but difficult. In this study, we aimed to assess the significance of compound motor action potential (CMAP) amplitude in patients identified through a newborn screening program. METHODS: We initiated a large-scale population newborn screening program for SMA in Taiwan in 2014. Patients had access to treatment through clinical trials or expanded use programs. Symptomatic patients were evaluated regularly, including CMAP exams. RESULTS: Among 364,000 screened newborns, 21 were diagnosed with SMA. The incidence of SMA was around 1 in 17,000 live births, and 70% developed SMA type 1. All infants with two SMN2 copies became symptomatic before the age of 1 month. CMAP amplitudes of 12 newborns were available, including 6 who were subsequently treated with nusinersen. We found that a rapid decrease of CMAP amplitude was an early predictor of symptom onset. Pretreatment CMAP and rapid increment of post-treatment CMAP could predict better treatment outcomes. CONCLUSION: This study prospectively demonstrated the incidence of SMA and its types. Our results imply the importance of pretreatment CMAP amplitude and rapid reversal of post-treatment CMAP amplitude with regard to disease presentation and also treatment outcomes.
PURPOSE: Early identification and treatment of spinal muscular atrophy (SMA) are crucial but difficult. In this study, we aimed to assess the significance of compound motor action potential (CMAP) amplitude in patients identified through a newborn screening program. METHODS: We initiated a large-scale population newborn screening program for SMA in Taiwan in 2014. Patients had access to treatment through clinical trials or expanded use programs. Symptomatic patients were evaluated regularly, including CMAP exams. RESULTS: Among 364,000 screened newborns, 21 were diagnosed with SMA. The incidence of SMA was around 1 in 17,000 live births, and 70% developed SMA type 1. All infants with two SMN2 copies became symptomatic before the age of 1 month. CMAP amplitudes of 12 newborns were available, including 6 who were subsequently treated with nusinersen. We found that a rapid decrease of CMAP amplitude was an early predictor of symptom onset. Pretreatment CMAP and rapid increment of post-treatment CMAP could predict better treatment outcomes. CONCLUSION: This study prospectively demonstrated the incidence of SMA and its types. Our results imply the importance of pretreatment CMAP amplitude and rapid reversal of post-treatment CMAP amplitude with regard to disease presentation and also treatment outcomes.
Entities:
Keywords:
SMA type; compound motor action potential (CMAP); incidence; nusinersen; outcome
Authors: Bo Hoon Lee; Stella Deng; Claudia A Chiriboga; Denise M Kay; Obehioya Irumudomon; Emma Laureta; Leslie Delfiner; Simona O Treidler; Yaacov Anziska; Ai Sakonju; Chelsea Kois; Osman Farooq; Kristin Engelstad; Alexandra Laurenzano; Katherine Hogan; Michele Caggana; Carlos A Saavedra-Matiz; Colleen F Stevens; Emma Ciafaloni Journal: Neurology Date: 2022-07-14 Impact factor: 11.800