SMN1 and proximal spinal muscular atrophy: While most cases of SMA result from a complete loss of SMN1, partial deletions in SMN1 have been identified in some samples from SMA patients—as well as in healthy controls—using PCR [142,143], microsatellite analysis [85,143], MLPA [83,85,108,110,127,142], whole-genome sequencing [120,135], long-range PCR [129] and dPCR [93].