Number of participants in the IEM* group: methylmalonic acidemia (5), ornithine transcarbamylase deficiency (7), citrullinemia (1); number of participants in the IEM** group: ornithine transcarbamylase deficency (7), argininosuccinic aciduria (4), methylmalonic acidemia (6), PA (3), MSUD (1), tyrosinemia type I (5), classical homocystinuria (4), lysinuric protein intolerance (1), 2-amino-/2-oxoadipic aciduria (1), hyperinsulinaemia–hyperammonaemia syndrome (1); medical food for patients:a: Phenex-1, -2; b: Phenyl-Free; c: XP Maxamaid/Maxamum. This evidence concerns the gene OTC and homocystinuria.