Promoter mutation is a common variant in GJC2-associated Pelizaeus-Merzbacher-like disease

► Pelizaeus-Merzbacher-like disease is an autosomal recessively inherited disorder. ► We identified a common GJC2 mutation in three families with PMLD. ► The promoter region mutation (c.-167A>G) was detected in the non-coding exon 1. ► A common haplotype was identified consistent with a likely founder effect. ► GJC2 diagnostic testing should include sequencing of exon 1 in suspected PMLD.