SMA - CLINICAL: P.87 Shortening treatment initiation timeframe through prenatal/neonatal diagnosis of spinal muscular atrophy

Abstract

The use of SMN replacement therapies (nusinersen and onasemnogene) is dramatically altering the natural disease history of spinal muscular atrophy (SMA). Due to maximal benefit with early treatment, the American College of Obstetrics and Gynecology (ACOG) recommended that SMA be included on universal carrier screening for all pregnant women beginning 03/2017 and was added to RUSP recommendations for newborn screening (NBS) on 07/2018. With implementation of prenatal diagnosis and NBS for SMA, the goal is earlier treatment initiation and better clinical outcomes. This study aims to evaluate the success of these screening recommendations, and their effect on early treatment initiation. Retrospective chart review was conducted on all patients with SMA with 2 or 3 copies of SMN2 diagnosed at Children's Hospital of Philadelphia after 01/01/2017, when nusinersen became commercially available in the US. 19 patients were included. 5/19 (26%) had parental carrier testing prenatally; 2/5 received a prenatal diagnosis. Total of 32% (n = 6) of patients were diagnosed at < 1 month of age, 2/6 from NBS and 2/6 due to family history. Of the 12/19 patients born after ACOG SMA prenatal carrier screening recommendation was adopted, 5/12 (42%) mothers had confirmed SMA prenatal carrier testing. Of 6 patients diagnosed <1 month, average (avg) age at diagnosis was 1 week, with treatment initiated avg of 5 weeks later. In 13 patients diagnosed > 1 month, avg age at diagnosis was 22 months with treatment started avg of 3.8 months later. Most mothers of patients with SMA did not have recommended carrier screening, and even in those who did, < 50% received a prenatal diagnosis. By increasing prenatal diagnosis, clinicians have an opportunity to decrease the amount of time to initiate treatment, and can fully counsel on disease and treatment options prior to birth. This limited data emphasizes the need for increased awareness of the importance of prenatal diagnosis and early treatment initiation.