Plasma amino acid disturbance in infancy. I: Hypermethioninaemia and transient tyrosinaemia. Arch Dis Child

For 3 years a prospective screening survey for neonatal aminoacidopathies has been carried out by this Unit, covering five boroughs in the neigh-bourhood of the Royal Manchester Children's Hospital, representing about 5000 births per year. The finding during this survey of transient tyro-sinaemia in 49 newborn infants has already been reported (Wong, Lambert, and Komrower, 1967); with one exception the tyrosine level reverted to normal within 4 weeks of the initial test, during which time vitamin C (50 mg. daily) was given. The exception was a boy who showed consistent plasma tyrosine increases for 93 days in spite of vitamin C therapy. It is interesting to note that of 8 tyrosinaemic children investigated in detail b