tRNA splicing endonuclease mutations cause pontocerebellar hypoplasia

Frank Baas and colleagues report mutations in three of the four subunits of the tRNA-splicing endonuclease complex in families with two subtypes of pontocerebellar hypoplasia. The findings implicate tRNA processing in neurological disorders. Pontocerebellar hypoplasias (PCH) represent a group of neurodegenerative autosomal recessive disorders with prenatal onset, atrophy or hypoplasia of the cerebellum, hypoplasia of the ventral pons, microcephaly, variable neocortical atrophy and severe mental and motor impairments. In two subtypes, PCH2 and PCH4, we identified mutations in three of the four different subunits of the tRNA-splicing endonuclease complex. Our findings point to RNA processing as a new basic cellular impairment in neurological disorders.