Hereditary spastic paraplegia with thin corpus callosum – childhood onset in two patients

Background: The hereditary spastic paraplegias (HSPs) are a group of rare disorders with the predominant clinical feature of spastic gait. They are subdivided into pure and complicated forms according to whether the disorder is associated with other neurologic abnormalities. Autosomal dominant, recessive and X-linked forms of HSP have been defined.

Patients: Two unrelated German patients, a 24-year-old woman (patient 1) and a 16-year-old girl (patient 2), had normal early motor and mental development: At 10 years (pat. 1) and 4 years (pat. 2) of age both showed progressive gait disturbance with spasticity and ataxia as well as cognitive impairment. They were wheelchair bound at 18 and 6 years of age. Patient 2 died at 16 years of age. No other members of their families were affected.

Results: MRI revealed mild diffuse non-progressive T2-signal alterations of cerebral white matter and very thin corpus callosum. Diagnostic workup failed to reveal any evidence for a infectious or metabolic disorder. Similarity of clinical symptoms and MRI patterns with the phenotype of Mast syndrome prompted mutation analysis of the SPG21 gene, encoding maspardin, which was normal. Clinical and neuroradiological features are diagnostic for autosomal recessive hereditary spastic paraplegia with thin corpus callosum (HSP-TCC). This condition has been described in Japan and, rarely, in American and European countries.

Conclusions: We report two patients with HSP-TCC with onset in childhood. This disorder with a characteristic MRI pattern may be considered as a complicated form of HSP associated with dementia and ataxia in children as well. Linkage to chromosome 15q13–15 has been reported in Japanese and Italian patients.

Keywords: spastic paraplegia, thin corpus callosum, dementia