TIMM17B and Early-onset X-linked optic atrophy: For example, the optic atrophy 2 (OPA2) linkage interval contains seven mitochondrial genes that include three known DG of which HSD17B10 is associated with optic atrophy [48]–[50], and three predicted DG of which two genes (NDUFB11, TIMM17B) interact with mitochondrial DG causing optic atrophy.