Hereditary spastic paraparesis: The real-world experience from a Neurogenetics outpatient clinic.

Introduction: Hereditary spastic paraplegias (HSP) are inherited disorders with progressive spastic gait disturbance. Advances in genetic research have improved their diagnosis but there is great uncertainty regarding the appropriate investigation strategies for HSPs. Our aim is to characterize a cohort of HSP, describing the phenotypic spectrum, genotype-specific differences and current functional status.

Methods: We performed a cross-sectional study with HSP affected patients in a tertiary center. We analyzed clinical features, diagnostic workup and follow-up of the patients.

Results: A total of 61 patients were identified with HSP. The median age of disease onset was 23 (IQR 30) years and a family history was positive in 73.8%. Most of them presented a pure phenotype and 52.4% had a confirmed genetic diagnosis: seventeen SPG4, four SPG11, two SPG7, two SPG78, one SPG3A, one SPG5, one SPG6, one SPG15, one SPG 31, one ARSACS and one X-ALD. Most families were diagnosed by single gene testing and, in six patients, molecular diagnosis was achieved with NGS techniques. In complex forms, the most striking clinical signs include cerebellar features in SPG7 and SPG78 and epilepsy in SPG6. After 24 (IQR 21) years of symptoms' onset, 60.4% of the patients are still able to walk independently and most of them engage in rehabilitation programs.

Conclusion: In our cohort, HSP is usually not a life-limiting disorder. Accurate molecular characterization is essential to optimize care for patients and their families. Well-phenotyped cohorts are important to direct further etiological and treatment investigations.