Pontocerebellar Hypoplasia, Type 2b, is also known as pontocerebellar hypoplasia type 2b, and has symptoms including clonus, muscle spasticity and opisthotonus. An important gene associated with Pontocerebellar Hypoplasia, Type 2b is TSEN2 (TRNA Splicing Endonuclease Subunit 2). Affiliated tissues include spinal cord and cerebellum, and related phenotypes are ventriculomegaly and cerebral atrophy