Huntington disease-like 3

Huntington disease-like 3 (HDL3) is an extremely rare neurodegenerative disorder that clinically resembles Huntington disease but is genetically distinct, as affected individuals do not carry the HTT gene CAG repeat expansion characteristic of classic Huntington disease. HDL3 was identified in a single Saudi Arabian family and has been mapped to chromosome 4p15.3. The condition is characterized by progressive neurological deterioration affecting the central nervous system, with onset typically in early childhood. Key clinical features include progressive dystonia, chorea, ataxia, gait abnormalities, and cognitive decline. Affected individuals may also develop spasticity, seizures, and behavioral changes. The disease follows a progressive course with significant motor and intellectual deterioration over time. Brain imaging may show caudate atrophy and cortical changes similar to those seen in Huntington disease. There is currently no cure or disease-modifying treatment for HDL3. Management is supportive and symptomatic, focusing on controlling movement abnormalities, managing seizures if present, and providing rehabilitative therapies. Given its extreme rarity, knowledge about this condition is limited to the original family description, and the causative gene has not yet been definitively identified.

Common questions about Huntington disease-like 3