03 July 2020
Further understanding Hereditary Spastic Paraplegia
Published online 20 October 2009
Hereditary spastic paraplegia (HSP) refers to a collection of heterogeneous genetic disorders, rather than a single disease. The main symptom common to all types is progressive spasticity in the lower limbs. In complex forms, however, this may be accompanied by neurological problems such as ataxia, mental retardation, dementia and epilepsy.
A group of researchers, mainly from France and Tunisia, determined that mutations in the gene ZFYVE26 were responsible for SPG15, which is one of the most common forms of HSP. Around 50% of all families diagnosed with SPG15 come from North Africa or the Middle East.
In total, 21 different mutations were found in this gene in SPG15 patients. The mutations were spread out across the whole spectrum of the gene, which can make clinical analysis of this condition complicated. The mutations were probably responsible for a total loss of the production of the protein spastizin, the exact function of which remains unknown, but is presumed to play a role in intracellular trafficking.
HSP is often accompanied by a thinning of the corpus callosum, which is a band of nerve cells that unites the two halves of the brain. SPG15 was found to be the second most common form of HSP with thin corpus callosum, following SPG11. While the researchers found significant differences between the two forms of the disease, they were not enough for use in clinical diagnosis of a single patient.