GJC2 and hypomyelinating leukodystrophy 2: The autosomal, recessively inherited Pelizaeus-Merzbacher-like disease 1 (PMLD1; MIM: 608804) is an early onset hypomyelinating leukodystrophy caused by mutations in the human connexin47 (Cx47) gene GJC2 (previously called GJA12; MIM: 608803) [1].