title: Evaluation and comparison of three assays for molecular detection of spinal muscular atrophy.
abstract: BACKGROUND
  Spinal muscular atrophy (SMA) is mainly caused by deletions in SMA-related genes. The objective of this study was to develop gene-dosage assays for diagnosing SMA.
  
  
  METHODS
  A multiplex, quantitative PCR assay and a CNVplex assay were developed for determining the copy number of SMN1, SMN2, and NAIP. Reproducibility and specificity of the two assays were compared to a multiple ligation-dependent probe amplification (MLPA) assay. To evaluate reproducibility, 30 samples were analyzed three times using the three assays. A total of 317 samples were used to assess the specificity of the two assays.
  
  
  RESULTS
  The multiplex quantitative PCR (qPCR) assay had higher reproducibility. Intra-assay CVs were 3.01%-8.52% and inter-assay CVs were 4.12%-6.24%. The CNVplex assay had ratios that were closer to expected (0.49-0.5 for one copy, 1.03-1.0 for two copies, and 1.50-1.50 for three copies). Diagnostic accuracy rates for the two assays were 100%.
  
  
  CONCLUSIONS
  The multiplex qPCR assay was a simple, rapid, and cost-effective method for routine SMA diagnosis and carrier screening. The CNVplex assay could be used to detect SMAs with complicated gene structures. The assays were reliable and could be used as alternative methods for clinical diagnosis of SMA.
authors.forename: Liang
authors.initials: L
authors.lastname: Li
authors.forename: Wan-Jun
authors.initials: WJ
authors.lastname: Zhou
authors.forename: Ping
authors.initials: P
authors.lastname: Fang
authors.forename: Ze-Yan
authors.initials: ZY
authors.lastname: Zhong
authors.forename: Jian-Sheng
authors.initials: JS
authors.lastname: Xie
authors.forename: Ti-Zhen
authors.initials: TZ
authors.lastname: Yan
authors.forename: Jian
authors.initials: J
authors.lastname: Zeng
authors.forename: Xu-Hui
authors.initials: XH
authors.lastname: Tan
authors.forename: Xiang-Min
authors.initials: XM
authors.lastname: Xu
mesh_terms: D056915:DNA Copy Number Variations / Q000235:genetics*; D005819:Genetic Markers / Q000235:genetics*; D005838:Genotype; D006801:Humans; D060885:Multiplex Polymerase Chain Reaction; D009134:Muscular Atrophy, Spinal / Q000175:diagnosis* / Q000235:genetics; D051616:Neuronal Apoptosis-Inhibitory Protein / Q000235:genetics*; D015203:Reproducibility of Results; D017384:Sequence Deletion; D055533:Survival of Motor Neuron 1 Protein / Q000235:genetics*; D055540:Survival of Motor Neuron 2 Protein / Q000235:genetics
chemical_list: D005819:Genetic Markers; C496800:NAIP protein, human; D051616:Neuronal Apoptosis-Inhibitory Protein; C526471:SMN1 protein, human; C526477:SMN2 protein, human; D055533:Survival of Motor Neuron 1 Protein; D055540:Survival of Motor Neuron 2 Protein