Spinocerebellar Ataxia 18, also known as spinocerebellar ataxia type 18, is related to spastic paraparesis and aceruloplasminemia, and has symptoms including tremor and dysdiadochokinesis. An important gene associated with Spinocerebellar Ataxia 18 is IFRD1 (Interferon Related Developmental Regulator 1). Affiliated tissues include skeletal muscle, and related phenotypes are muscle weakness and areflexia