Charcot-Marie-Tooth Disease, X-Linked (GJB1)
X-linked Charcot-Marie-Tooth disease is a pan-ethnic disorder that is caused by pathogenic variants in the GJB1 gene. It is inherited in an X-linked manner, and therefore males are affected more often and more severely than females. Patients with this condition will have a progressive weakness and loss of sensation in the feet, ankles, and hands. The first symptoms will typically develop before the age of 25, but patients will often have long periods of stabilization. This variant of Charcot-Marie-Tooth disease is also associated with hearing loss, but not all patients will develop this symptom. Lifespan is not affected. Patients with nonsense variants typically have an earlier onset and more severe disease than those with a missense variant. Several pathogenic variants have been correlated with the presence of specific symptoms, and therefore the disease severity may be able to be predicted in some patients.
For information about carrier frequency and residual risk, please see the Expanded Carrier Screen brochure.