Rab18 Collaborates with Rab7 to Modulate Lysosomal and Autophagy Activities in the Nervous System: an Overlapping Mechanism for Warburg Micro Syndrome and Charcot-Marie-Tooth Neuropathy Type 2B.
Four missense mutations in the late endosomal Rab7 GTPase (L129F, K157N, N161T, and V162M) cause the autosomal dominant peripheral neuropathy Charcot-Marie-Tooth type 2B (CMT2B) disease.
We propose that Rab7 mutants induce premature degradation of retrograde NGF-TrkA trophic signaling, which may potentially contribute to the CMT2B disease.
Four missense mutations of Rab7, a small GTPase of the Rab family involved in intracellular vesicular trafficking, are associated with the CMT2B phenotype.
RAB7 mutations were only found in patients with a Charcot-Marie-Tooth type 2B (CMT2B) phenotype, an axonal sensory-motor neuropathy with pronounced ulcero-mutilations.
Altogether, these data demonstrate that all tested CMT2B-associated Rab7 mutations are mechanistically similar, suggesting that activated forms of the Rab7 are responsible for CMT2B disease.
There are two known autosomal dominant genes for the hereditary ulcero-mutilating neuropathies: SPTLC1 (hereditary sensory neuropathy type 1) and RAB7 (Charcot-Marie-Tooth disease type 2B).
We refined the CMT2B locus to a 2.5-cM region and report two missense mutations (Leu129Phe and Val162Met) in the small GTP-ase late endosomal protein RAB7 which causes the CMT2B phenotype in three extended families and in three patients with a positive family history.