Defects in GJC2 are the cause of leukodystrophy hypomyelinating type 2 (HLD2) [MIM:608804]; also known as Pelizaeus-Merzbacher-like disease autosomal recessive type 1. HLD2 is an autosomal recessive hypomyelinating leukodystrophy characterized by nystagmus, impaired motor development, ataxia, choreoathetotic movements, dysarthria and progressive spasticity.