Autosomal dominant spastic paraplegia type 42

Autosomal dominant spastic paraplegia type 42 (SPG42) is an extremely rare hereditary spastic paraplegia caused by mutations in the SLC33A1 gene, which encodes acetyl-CoA transporter protein. This gene plays a critical role in transporting acetyl-CoA into the endoplasmic reticulum, and disruption of its function leads to progressive degeneration of the upper motor neurons in the corticospinal tract. The disease primarily affects the nervous system, specifically the long motor nerve fibers (axons) that connect the brain to the spinal cord and control voluntary movement of the lower limbs. The hallmark clinical feature of SPG42 is progressive spasticity and weakness of the lower extremities, leading to increasing difficulty with walking and gait disturbance. Patients typically develop symptoms in childhood or adolescence, though the age of onset can vary. Additional features may include hyperreflexia (exaggerated reflexes), extensor plantar responses (Babinski sign), and urinary urgency. The condition is classified as a "pure" form of hereditary spastic paraplegia, meaning neurological involvement is largely limited to lower limb spasticity without significant additional neurological or systemic complications, although some variability in clinical presentation has been reported. There is currently no cure or disease-modifying treatment for SPG42. Management is symptomatic and supportive, focusing on physical therapy to maintain mobility and reduce spasticity, antispasticity medications such as baclofen or tizanidine, and orthopedic interventions as needed. The condition was first described in a Chinese family with multiple affected members across several generations, and only a very limited number of families have been reported worldwide.

Common questions about Autosomal dominant spastic paraplegia type 42