Regarding Duane retraction syndrome, which can be considered a congenital cranial dysinnervation disorder [9], a dominant familial form (DURS2) was linked in a large pedigree to 2q31 [14] and is now known to be caused by heterozygous mutation in chimerin 1 (CHN1) [15]. The gene discussed is CHN1; the disease is Duane retraction syndrome.