32 genes: SPG1 (L1CAM), SPG11, SPG4 (SPAST), SPG20, SPG3A (ATL1), SPG17 (BSCL2), SPG9A (ALDH18A1), SPG35 (FA2H), SPG5A(CYP7B1), SPG6 (NIPA1), SPG2 (PLP1), SPG12 (RTN2), SPG31 (REEP1), SPG10 (KIF5A), SPG50 (AP4M1), SPG51 (AP4E1), SPG47 (AP4B1), SPG52 (AP4S1), SPG15 (ZFYVE26), SPG55 (C12orf65), SPG7, SPG30 (KIF1A), SPG64 (ENTPD1), SPG42 (SLC33A1), SPG9B (ALDH18A1), SPG13 (HSPD1), SPG8 (KIAA0196), SPG18 (ERLIN2), SPG33 (ZFYVE27), SPG48 (AP5Z1), SPG43 (C19orf12), SPG39 (PNPLA6)