Mutations in RARS2 have been reported in patients with pontocerebellar hypoplasia type 6 (PCH6, OMIM 611523).2, 6, 7, 8, 9, 10, 11, 12 The gene encodes the mitochondrial aminoacyl‐tRNA synthetase (ARS) enzyme, arginyl transfer RNA synthetase (MIM 611524). Here, MTSS1 is linked to pontocerebellar hypoplasia type 6.