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MIM.605704 Chr.20

Thursday 24 April 2008

SNAREs are compartmentally specific, cytoplasmically oriented integral membrane proteins involved in the fusion of membranes and the transport of intracellular proteins.

Recognition of vesicles and target membranes is mediated by v-SNAREs and t-SNAREs.


- germline mutations in late-onset spinal muscular atrophy (15372378)
- germline mutations in amyotrophic lateral sclerosis (ALS) (15372378)

A dominant missense mutation on chromosome 20 in a set of seven kindreds has been linked to a heterogeneous ALS course, with most instances of disease representing an atypical ALS that is accompanied by an unusual tremor.

About one-fourth of affected individuals in the same families develop a late-onset spinal muscular atrophy, and a small proportion of patients develop symptoms of classic ALS.

All instances apparently derive from a common mutation in the gene encoding vesicle-associated membrane protein B (VAPB), also known as synaptobrevin-associated protein B.

VAPB has been implicated in endoplasmic reticulum to Golgi transport, albeit other roles in membrane transport, including axonal transport of membrane components, are likely as well.

It is unknown how the corresponding proline-to-serine substitution at position 56 affects the functional properties of the ubiquitously expressed VAPB.

See also

- motor neuron diseases (MNDs)
- ALS genes