Neonatal screening for spinal muscular atrophy: Report of a multicenter study in Brazil.

Spinal muscular atrophy (SMA) is considered one of the most common autosomal recessive disorders, with an estimated incidence of 1 in 10,000 live births. Testing for SMA has been recommended for inclusion in neonatal screening (NBS) panels since there are several therapies available and there is evidence of greater efficacy when introduced in the pre/early symptomatic phases. In the present study, dried blood spot samples collected by the Reference Services of Neonatal Screening of the Brazilian states of Rio Grande do Sul, Sao Paulo, Mato Grosso and Bahia to perform the routine NBS panel were also screened for 5q-SMA, using real-time PCR (SALSA MC002 technique). In this study, samples from 80,000 newborns were analyzed, enabling the identification of 7 5q-SMA cases, which were confirmed by multiplex ligation-dependent probe amplification (MLPA). Considering our findings, Brazil has an incidence of 5q-SMA of 1 in 11,428 live births. This work expands regional knowledge about the incidence of SMA and is fundamental for planning the implementation of screening for this condition in Brazil.