ARL2BP and mitochondrial DNA depletion syndrome: The remaining cases consisted of Kearns-Sayre syndrome (n = 2); ARL2BP-associated ciliopathy [14] (n = 2); polyneuropathy, hearing loss, ataxia, retinitis pigmentosa, and cataract (PHARC) (n = 2); pantothenate kinase-associated neurodegeneration (PKAN) (n = 2); bone marrow failure syndrome type 3 (n = 1); neuropathy, ataxia, retinitis pigmentosa (NARP) (n = 1); Jalili syndrome (n = 1), and a presumed mitochondrial DNA depletion syndrome (n = 1), as shown in Fig. 2.