Oxford JournalsMedicine & HealthScience & MathematicsHuman Molecular Genetics Volume 11 Issue 23Pp. 2837-2844                                                                                             Charcot–Marie–Tooth disease neurofilament mutations disrupt neurofilament assembly and axonal transport Janet Brownlees et al             

Charcot–Marie–Tooth disease (CMT) is the most common inherited disorder of the peripheral nervous system, and mutations in neurofilaments have been linked to some forms of CMT. Neurofilaments are the major intermediate filaments of neurones, but the mechanisms by which the CMT mutations induce disease are not known. Here, we demonstrate that CMT mutant neurofilaments disrupt both neurofilament assembly and axonal transport of neurofilaments in cultured mammalian cells and neurones. We also show that CMT mutant neurofilaments perturb the localization of mitochondria in neurones. Accumulations of neurofilaments are a pathological feature of several neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), Alzheimer's disease, Parkinson's disease, dementia with Lewy bodies, and diabetic neuropathy. Our results demonstrate that aberrant neurofilament assembly and transport can induce neurological disease, and further implicate defective neurofilament metabolism in the pathogenesis of human neurodegenerative diseases.

Does this suggest that CMT can cause Alzheimer's and what about in people with Down's syndrome?

No, the correlation is between CMT and functional dyspepsia.

Trisomy 21 (Downs Syndrome) is correlated with early onset Alzheimer's disease (AD). Patients with trisomy 21 are much more likely to develop AD. Chromosome 21 houses amyloid precursor protein (APP), which is a precursor to beta-amyloid, implicated in development of amyloid plaques and dementia.

Down Syndrome is correlated to early onset Alzheimer's disease. The risk is much greater than any other population.