Clinical and molecular characterization of hereditary spastic paraplegia in a spanish Southern region.

Introduction: Spastic paraplegia (SPG) is a syndrome characterised by lower limb spasticity, occurring alone or in association with other neurological manifestations. Despite of the new molecular technologies, many patients remain yet undiagnosed.

Objective: The purpose of this study was to describe the clinical presentation and molecular characteristics of a cohort of 27 patients from 18 different families with SPG in the south of Spain.

Methods: We used a targeted next-generation sequencing (NGS) approach to study a proband from each family.

Results: Variants in gene were the most common cause of SPG in our area. We made a genetic diagnosis in 52% of cases, identified 3 novel variants and reclassified one uncertain variant in gene as pathogenic variant. We identified a patient with two truncanting mutations in gene and late onset disease and report another missense mutation outside of motor domain of gene in a family with pure SPG.

Conclusion: Our study contributes to enhance the scientific knowledge of SPG. It is important to note the large group of cases (48%) that were not genetically diagnosed in our cohort. Therefore NGS approach is an efficient diagnostic tool, but it still large the number of non-diagnosed subjects, suggesting further genetic heterogeneity.