A Novel Homozygous Founder Variant of RTN4IP1 in Two Consanguineous Saudi Families

The genetic architecture of mitochondrial disease continues to expand and currently exceeds more than 350 disease-causing genes. Bi-allelic variants in RTN4IP1, also known as Optic Atrophy-10 (OPA10), lead to early-onset recessive optic neuropathy, atrophy, and encephalopathy in the afflicted patients. The gene is known to encode a mitochondrial ubiquinol oxidoreductase that interacts with reticulon 4 and is thought to be a mitochondrial antioxidant NADPH oxidoreductase. Here, we describe two unrelated consanguineous families from the northern region of Saudi Arabia harboring a missense variant (RTN4IP1:NM_032730.5; c.475G