Late-Onset Sandhoff Disease

Late-Onset Sandhoff disease is a rare form of Sandhoff disease, a lysosomal storage disorder caused by dysfunctional enzymes Hexosaminidase A (Hex-A) and Hexosaminidase B (Hex-B). Because only a low level of Hex-A and Hex-B is functional in patients with Late-Onset Sandhoff, the symptoms typically presents in adolescence, with dysarthria, proximal (trunk) muscle weakness, tremor and ataxia. Muscle cramps, especially in the legs at night, and fasciculations (muscle twitching) are common. Not all symptoms are present in every individual affected by the disease; weakness of the proximal muscles, however, is a symptom common to all. Examples of trunk muscle weakness may include difficulty rising from a seated position, trouble getting out of bed, struggling to balance while getting dressed. Patients with Late-Onset Sandhoff have a high risk of dementia, which often correlates with other neurologic manifestations.

As a recently recognized rare form along the Sandhoff continuum, the course of Late-Onset Sandhoff is not completely known. Late-Onset Sandhoff differs from the juvenile form primarily in its impact of intelligence, which is minimal in patients with Late-Onset Sandhoff. Life expectancy of patients affected by Late-Onset Sandhoff is probably not reduced. Affected individuals understandably report feelings of isolation and uncertainty as to what to anticipate as the disease progresses. Social and academic difficulties, resulting from the physical and psychiatric manifestations of the disease, are also a concern.

Please review the Living with LOTS section under Member Support Services for more information on dealing with Late-Onset Sandhoff. Late Onset Tay-Sachs and Late Onset Sandhoff have similar symptoms, progress, issues and management.