Novel heterozygous STUB1 gene mutation causes SCA48 in a Hungarian patient

Abstract

Spinocerebellar ataxia type 48 (SCA48) is an autosomal dominantly inherited disease characterized by gait and limb ataxia, cerebellar dysarthria, cognitive impairment, psychiatric abnormalities and variable types of movement disorders. To date, more than 30 STUB1 gene (NM_005861.4) mutations have been described in the genetic background of SCA48. The aim of this short report was to demonstrate the first Hungarian SCA48 patient caused by a novel STUB1 missense mutation (c.788G>C, p.Arg263Pro). The characteristics of detailed neurological phenotype, brain MRI and genetic assessment are presented and compared to previously published cases. The most important neurological findings of the patient were gait ataxia, dysarthria, cognitive decline and psychiatric problems including depression, anxiety and mild impulsivity. The brain MRI demonstrated cerebellar atrophy with posterolateral predominance and frontal lobe cortical atrophy. Clinical exome sequencing examination identified the above-mentioned missense variant located in the significant ubiquitinase domain of the CHIP protein. In this paper the first Hungarian SCA48 patient was described with characteristic neuropsychiatric signs and brain MRI abnormalities, due to a novel STUB1 gene missense mutation.