WDR41 and Smith-Magenis syndrome: In agreement with the bioinformatics prediction, recent studies have shown that C9orf72 is part of a protein complex containing Smith-Magenis syndrome chromosomal region candidate gene 8 (SMCR8) and WD repeat containing protein 41 (WDR41) [1, 21, 45, 48, 51, 54, 57], and that this complex possesses GEF activity for RAB8A and RAB39B, two Rabs involved in autophagy [45, 57].