SMN1 and spinal muscular atrophy: Similarly, exome and Sanger sequencing have been used to characterize an SVA-F retrotransposon in SMN1 intron 7 as a novel mutational cause of spinal muscular atrophy (16), and PCR combined with Sanger sequencing identified an SVA retrotransposon insertion in ITGB3 in a family with Glanzmann thrombasthenia (17).