SPG11 compound mutations in spastic paraparesis with thin corpus callosum

Area of Science:

• Genetics
• Neurology
• Metabolic Imaging

Background:

• Autosomal recessive hereditary spastic paraparesis with thin corpus callosum (ARHSP-TCC) is an increasingly recognized neurological disorder.
• SPG11 gene mutations have been previously linked to ARHSP-TCC.

Observation:

• This study investigated SPG11 gene involvement in four new individuals with recessive or sporadic HSP-TCC.
• Genetic analysis identified four novel frameshift/nonsense mutations and the R2034X mutation in SPG11, all in heterozygous compound status.
• Positron Emission Tomography (PET) revealed decreased thalamic and bilateral paracentral frontal lobe metabolism in affected individuals.

Findings:

• Loss-of-function SPG11 mutations are a primary cause of ARHSP-TCC in Southern Europe.
• This causality extends to cases initially appearing as sporadic.
• Consistent decreased thalamic metabolism serves as a phenotypic hallmark for SPG11 mutations.

Implications:

• Identifying SPG11 mutations is crucial for diagnosing ARHSP-TCC, particularly in Southern European populations.
• Metabolic imaging, specifically assessing thalamic activity, can aid in diagnosing SPG11-related disorders.
• Further research into SPG11 function may reveal therapeutic targets for hereditary spastic paraplegia.