BBS1 and neuronal ceroid lipofuscinosis 7: Alterations from multiple TEs, most notably from L1, Alu, and SINE-VNTR-Alu (SVA) insertions, have more generally been described as the underlying genetic cause in patients with IRDs, such as insertion of an SVA F retrotransposon in the Bardet-Biedl syndrome 1 (BBS1) gene in patients with BBS, and an intronic SVA insertion in the major facilitator superfamily domain containing 8 (MFSD8) gene in a patient with CLN7 form of the Batten disease [11, 12].