Spinal Muscular Atrophy Neonatal Screening Program

Drops of blood from a puncture from the newborn's heel are collected, dried for 24 hours at room temperature and then sent to the laboratory for analysis. The screening test is a first-level molecular genetic test that allows the identification of patients affected by SMA who present the homozygous deletion of exon 7 of the SMN1 gene using the Real Time polymerase chain reaction (PCR) technique. This qualitative method is based on the use of specific fluorescent probes that discriminate the SMN1 gene from its survival motor neuron 2 (SMN2) homologue and also allow the quality assessment of genomic DNA through amplification of an internal control gene. When a positive testing patient is identified, the birth center is promptly notified to call the family and carry out a further blood sample aimed at confirming the possible diagnosis with a second level test.