Establishment of a Pilot Newborn Screening Program for Spinal Muscular Atrophy in Saint Petersburg

• Published in: International Journal of Neonatal Screening
• Main Authors: Anton Kiselev, Marianna Maretina, Sofia Shtykalova, Haya Al-Hilal, Natalia Maslyanyuk, Mariya Plokhih, Elena Serebryakova, Marina Frolova, Natalia Shved, Nadezhda Krylova, Arina Il’ina, Svetlana Freund, Natalia Osinovskaya, Iskender Sultanov, Anna Egorova, Anastasia Lobenskaya, Alexander Koroteev, Irina Sosnina, Yulia Gorelik, Olesya Bespalova, Vladislav Baranov, Igor Kogan, Andrey Glotov
• Format: Article
• Language: English
• Published: MDPI AG 2024-01-01
• Subjects: spinal muscular atrophy; newborn screening; <i>SMN1</i>; <i>SMN2</i>; real-time PCR; dried blood spots
• Online Access: https://www.mdpi.com/2409-515X/10/1/9

Spinal muscular atrophy 5q (SMA) is one of the most common neuromuscular inherited diseases and is the most common genetic cause of infant mortality. SMA is associated with homozygous deletion of exon 7 in the <i>SMN1</i> gene. Recently developed drugs can improve the motor functions of infants with SMA when they are treated in the pre-symptomatic stage. With aim of providing an early diagnosis, newborn screening (NBS) for SMA using a real-time PCR assay with dried blood spots (DBS) was performed from January 2022 through November 2022 in Saint Petersburg, which is a representative Russian megapolis. Here, 36,140 newborns were screened by the GenomeX real-time PCR-based screening test, and three genotypes were identified: homozygous deletion carriers (4 newborns), heterozygous carriers (772 newborns), and wild-type individuals (35,364 newborns). The disease status of all four newborns that screened positive for the homozygous <i>SMN1</i> deletion was confirmed by alternate methods. Two of the newborns had two copies of <i>SMN2</i>, and two of the newborns had three copies. We determined the incidence of spinal muscular atrophy in Saint Petersburg to be 1 in 9035 and the SMA carrier frequency to be 1 in 47. In conclusion, providing timely information regarding <i>SMN1</i>, confirmation of disease status, and <i>SMN2</i> copy number as part of the SMA newborn-screening algorithm can significantly improve clinical follow-up, testing of family members, and treatment of patients with SMA.