As an example, we used Fibroblast Growth Factor 14 (FGF14), which is highly expressed in wild type cerebellar Purkinje neurons [10], [11] and in which a mutation causes Spinocerebellar ataxia, type 27 (SCA27) in humans [12]–[15]. The gene discussed is FGF14; the disease is spinocerebellar ataxia type 27.