Although bi-allelic single nucleotide polymorphism (SNP)–based karyomapping has been used in linkage analysis for PGT-M of SMA (Konstantinidis et al., 2015), the SNP coverage at the SMN1 locus is relatively low, thus reducing reliability of this method for SMA PGT-M. This evidence concerns the gene SMN1 and proximal spinal muscular atrophy.