[Application of droplet digital PCR technology for genetic testing and prenatal diagnosis of spinal muscular atrophy].

To explore the clinical application of droplet digital PCR (ddPCR) for genetic testing and prenatal diagnosis of spinal muscular atrophy (SMA) with deletion of SMN1 gene exon 7.A total of 138 clinical samples, including 121 peripheral blood, 13 amniotic fluid, 2 umbilical cord blood and 2 chorionic villi from 56 SMA families, were tested by both ddPCR and multiplex ligation-dependent probe amplification (MLPA). Results of the two approaches were analyzed with commercial software QuantaSoft (ddPCR) and Coffalyser (MLPA), respectively.Among the 138 cases, 25 had two copies, 84 had one copy, and 29 had null copy of exon 7 of the SMN1 gene. The results of ddPCR and MLPA were completely consistent.As a rapid, precise and economically efficient method, ddPCR will provide a new choice for genetic testing of SMA.