Novel mutation of SPG4 gene in a Chinese family with hereditary spastic paraplegia: A case report

BACKGROUND: Hereditary spastic paraplegia (HSP) is a group of neurogenetic diseases of the corticospinal tract, accompanied by distinct spasticity and weakness of the lower extremities. Mutations in the spastic paraplegia type 4 (SPG4) gene, encoding the spastin protein, are the major cause of the disease. This study reported a Chinese family with HSP caused by a novel mutation of the SPG4 gene. CASE SUMMARY: A 44-year-old male was admitted to our hospital for long-term right lower limb weakness, leg stiffness, and unstable walking. His symptoms gradually worsened, while no obvious muscle atrophy in the lower limbs was found. Neurological examinations revealed that the muscle strength of the lower limbs was normal, and knee reflex hyperreflexia and bilateral positive Babinski signs were detected. Members of his family also had the same symptoms. Using mutation analysis, a novel heterozygous duplication mutation, c.1053dupA, p. (Gln352Thrfs*15), was identified in the SPG4 gene in this family. CONCLUSION: A Chinese family with HSP had a novel mutation of the SPG4 gene, which is autosomal dominant and inherited as pure HSP. The age of onset, sex distribution, and clinical manifestations of all existing living patients in this family were analyzed. The findings may extend the current knowledge on the existing mutations in the SPG4 gene.