Hypothesis: To characterize and describe disease progression and heterogeneity of the
This research study seeks to develop a quantitative method to delineate disease progression
for the gangliosidosis diseases (Tay-Sachs disease, Sandhoff disease, and GM1 gangliosidosis)
in order to better understand the natural history and heterogeneity of these diseases. Such a
quantitative method will also be essential for evaluating any treatments that may become
available in the future, such as gene therapy. The data from this study will be necessary to
provide end-points for future therapies, guide medical decisions about treatment, provide
objective measurement of treatment outcomes, and accurately inform parents regarding
The infantile form of GM2 and GM1 gangliosidosis diseases ("classic" infantile) is the most
common. Infants with Tay-Sachs disease, Sandhoff disease or GM1 gangliosidosis appear normal
at birth, but at approximately 6-10 months of age begin to manifest progressive weakness and
loss of muscle strength, such as loss of the ability to sit up or turn over. They may
evidence deafness, and display decreased attentiveness. This is followed by rapid
deterioration of motor skills and slowed mental development (neurodegeneration), often with
seizures. Retinal involvement leads to visual impairment and eventual blindness. Death
typically occurs by the age of five. Currently there is no treatment for Tay-Sachs disease,
Sandhoff disease or GM1 gangliosidosis.
Late Onset Tay-Sachs disease ("LOTS") occurs in patients beginning in their twenties or
thirties, and is characterized by poor motor coordination and psychotic behaviors. Patients
with LOTS also have decreased life expectancy, although to a lesser degree than those with
infantile or juvenile Tay-Sachs or Sandhoff diseases. Currently there is no treatment for
This study is comprised of two different 'arms.' The first arm, entitled Aim 1, will focus on
the developmental course of infantile and juvenile Tay-Sachs disease, Sandhoff disease, and
GM1 gangliosidosis. Longitudinal data from individuals with these diseases will be collected
in order to delineate the natural history of these diseases. This data will help to objectify
disease progression, and can be used to create a disease stage and severity index.
The second arm, entitled Aim 2, will focus on LOTS and will seek to understand the
progression of central nervous system disease, with special focus upon cerebellar and frontal
systems. This will be accomplished by using quantitative methods including neuroimaging and
neuropsychological measures that explore motor and executive functions, visual-spatial and
1. Subjects must have a documented gangliosidosis disease.
2. Subjects must be able to complete appropriate neuropsychological and neurobehavioral
3. Late-onset gangliosidosis subjects must be able to tolerate a head MRI.
1. There are no exclusion criteria, beyond a desire not to participate.