INTRODUCTION. Hereditary spastic paraplegia (HSP) comprises a heterogeneous group of rare neurodegenerat ive disorders characterized by progressive spasticity and hyperreflexia of the legs. Many aspects of this disorder are studied poorly if at all. It was never studied systematically in Estonia.
AIMS. The aims of this study were to evaluate the overall prevalence of HSP in Estonia, to detect new mutations in the SPAST gene, to characterize the phenotype of Estonian patients with HSP caused by mutations in the SPAST gene, to examine the relative impact of HSP on the health related quality of life (HRQoL) experienced by the HSP population in Estonia.
METHODS. A multi-source approach was used to calculate the prevalence of HSP in Estonia. The PCR products of all samples were screened by denatur ing high-performance liquid chromatography. To screen all samples for SPAST copy number aberrations, a multiplex ligationdependent probe amplification assay was used. Sporadic cases with a normal DHPLC profi le were not sequenced; all other cases underwent sequencing. The HRQoL was evaluated using a RAND 36-Item Health Survey 1.0 questionnaire.
RESULTS. The crude prevalence rate of HSP in Estonia was found to be 4.4 per 100,000 individuals. Twelve changes in the SPAST gene were detected and confirmed, of which ten were new. The HRQoL was lower in persons with HSP, being affected mostly by reduced physical abilities, which can be expected based on the nature of this neurological disorder.
CONCLUSIONS. Our finding of a crude prevalence of 4.4 per 100,000 individuals is consistent with previous reports from studies performed elsewhere. We have identified new changes in the SPAST gene. The HRQoL in patients with HSP was found to be significantly lower than that for the general population.