A multiplex allele specific PCR capillary electrophoresis (mASPCR-CE) assay for simultaneously analysis of SMN1/SMN2/NAIP copy number and SMN1 loss-of-function variants.

Objectives: Spinal muscular atrophy (SMA) is a severe inherited neuromuscular disorder with a high carrier frequency and incidence rate. An accurate molecular method for SMA genes is crucial in carrier screening, clinical diagnosis, outcome assessment and precision therapies.

Methods: Comprehensively using the multiplex allele specific PCR (mASPCR) and capillary electrophoresis (CE), a novel single tube assay was developed to simultaneously determine the copy number of SMN1/SMN2/NAIP genes and five common loss-of-function variants in SMN1. A total of 283 genotype known subjects were detected to evaluate the accuracy, while 564 clinical random samples were double-blind detected with this assay and MLPA to assess the specificity and sensitivity.

Results: This assay had high accuracy of 100 % consistency with the predetermined values in 283 genotype known subjects. Among 564 clinical random samples, the correlation between this assay and comparative method was 100 %, which showing high specificity and sensitivity.

Conclusions: This mASPCR-CE assay is easy to use and cost-effective, making it suitable for routine use in molecular screening and clinical diagnosis of SMA.