In the first case, the presence of Alpha-Fetoprotein (AFP) levels below 15 μg/L can orient the diagnosis towards AOA1 rather than AOA2 [29], while the occurrence of spastic paraplegia should suggest SPG7 above SCAR10 [30], that furthermore typically shows low Coenzyme Q10 (CoQ10) values [9]. The gene discussed is AFP; the disease is Spastic paraplegia.