This report describes Charcot-Marie-Tooth disease, axonal, type 2A2B (CMT2A2B), which is a subtype of Charcot-Marie-Tooth disease. CMT2A2B exhibits autosomal recessive inheritance. The human gene implicated in this disease, MFN2, is implicated in several related diseases. See the report for 'Charcot-Marie-Tooth disease, MFN2-related' (FBhh0000087) for information on experimental results using Drosophila models of this and related diseases.
[updated Feb. 2020 by FlyBase; FBrf0222196]
Charcot-Marie-Tooth disease (CMT) constitutes a clinically and genetically heterogeneous group of hereditary motor and sensory peripheral neuropathies. CMT is divided into several major types: Type 1 is characterized by demyelination and by a significantly slowed motor median nerve conduction velocity (NCV). Type 2 is characterized by axonal abnormalities and a normal or slightly reduced NCV. "Intermediate" types describe CMT families with nerve conduction velocities, in different affected individuals, that overlap the division between Type 1 and Type 2. Additional types are defined on the basis inheritance patterns. [from MIM:609260 and MIM:606482; 2015.12.15]
Symptoms typically include progressive distal muscle weakness and atrophy, often associated with mild to moderate sensory loss, depressed tendon reflexes, and high-arched feet. [from Gene Reviews, http://www.ncbi.nlm.nih.gov/books/NBK1358 2015.12.15]
[CHARCOT-MARIE-TOOTH DISEASE, AXONAL, AUTOSOMAL RECESSIVE, TYPE 2A2B; CMT2A2B](https://omim.org/entry/617087)
[MITOFUSIN 2; MFN2](https://omim.org/entry/608507)
Autosomal recessive axonal CMT2A2B is a neurologic disorder characterized by onset of peripheral neuropathy in the first years of life. Patients have difficulty walking due to distal muscle weakness; upper limbs may also be affected. Sensory impairment is more variable. Patients often have optic atrophy (summary by Polke et al., 2011; pubmed:21715711). [from MIM:617087; 2020.02.19]
Autosomal recessive axonal Charcot-Marie-Tooth disease type 2A2B (CMT2A2B) is caused by homozygous or compound heterozygous mutation in the MFN2 gene. [from MIM:617087; 2020.02.19]
MFN2 encodes a mitochondrial outer membrane GTPase that participates in mitochondrial fusion and contributes to the maintenance and operation of the mitochondrial network. [Gene Cards, MFN2; 2020.02.19]
