SNP Shot: Genomic Insights

Spastic paraplegia type 8 (SPG8) belongs to a category of genetic conditions called hereditary spastic paraplegias (HSPs). HSPs are defined by gradually increasing muscle stiffness (spasticity) and progressive paralysis (paraplegia) affecting the legs. HSPs are classified as either pure or complex. Pure HSPs primarily affect the nerves and muscles controlling the lower limbs and bladder function. Complex HSPs, on the other hand, involve more widespread nervous system involvement beyond these areas. SPG8 is classified as a pure form of hereditary spastic paraplegia.

Consistent with all HSPs, SPG8 presents with spasticity and weakness in the leg muscles. Individuals with SPG8 may also exhibit heightened reflexes (hyperreflexia), reduced sensitivity to vibrations, muscle atrophy (amyotrophy), and bladder control issues. Symptoms of SPG8 typically manifest during early to mid-adulthood. As muscle weakness and spasticity worsen over time, assistive devices such as canes, walkers, or wheelchairs may become necessary.

Inheritance:

SPG8 is inherited in an autosomal dominant manner. This means that only one copy of the mutated gene in each cell is enough to cause the condition. In the majority of cases, an affected individual inherits the altered gene from a parent who also has the condition. However, SPG8 can also arise from new, spontaneous mutations in the gene, occurring in individuals with no family history of the disorder.