All MFSD8 variants associated with isolated retinal dystrophy (MD, COD/CORD) are located in the transmembrane alpha helices (Figure 3), except p.(Glu381*), located at the most extracellular side of loop 9, nearby the two proteolytic cleavage sites Asn370 and Asn376. The gene discussed is MFSD8; the disease is inherited retinal dystrophy.