The GJA12/GJC2 (GJA12 was recently renamed GJC2) encodes the gap junction protein connexin47 (Cx47), which is a member of the connexin family of highly conserved integral membrane proteins. This gene is highly expressed in oligodendrocytes; it plays a key role in central myelination and is involved in peripheral myelination in humans. In addition, Gap channels are specialized cell-cell contacts that allow passive diffusion of molecules up to 1 kDa, including nutrients, metabolites (glucose), ions (K+, Ca2+) and second messengers (IP3, cAMP).
Defects in this protein are the cause of leukodystrophy, hypomyelinating, 2 (HLD2), lymphedema, hereditary, 1C (LMPH1C), and spastic paraplegia 44, autosomal recessive (SPG44).