Charcot-Marie-Tooth disease, type 4J (CMT4J) belongs to the genetically heterogeneous group of CMT peripheral sensorimotor polyneuropathy diseases.Last update: September 2008
CMT4J is rare, with only five patients reported in the literature so far.
The syndrome is characterized by rapidly progressive, asymmetric motor neuron degeneration with slow nerve conduction velocities, weakness and paralysis, without sensory loss.
It is caused by mutations in the FIG4 gene (6q21). This gene encodes the enzyme polyphosphoinositide phosphatase, which plays a key role in trafficking of intracellular organelles.
CMT4J is transmitted in an autosomal recessive manner.