96 DIFFERENTIAL DIAGNOSIS OF HYPERPHENYLALANI N-AEMIA (HPA) AND FOLLOW UP OF SEVEN PATIENTS WITH TETRAHYDROBIOPTERIN (BH4) DEFICIENCY

摘要

HPA is either due to phenylalanine hydroxylase deficiency or to BH4 deficiency. The latter should be excluded in all newborns with HPA using three methods: (1) oral BH4 loading test; (2) measurement of dihydropteridine reductase (DHPR) activity in erythrocytes; (3) investigation of the urinary pterin pattern. From 1979 until 1987 seven patients with BH4 deficiency have been detected in Munich. One of two girls with severe 6-pyruvoyl tetrahydropterin synthase (PTS) deficiency has been treated since the age of 7 weeks. Her psychomotor development is now, at the age of 11 years, normal whereas the other girl, 13 years of age, who has been treated since the age of 7 years, shows marked developmental delay. Three out of four patients with partial PTS deficiency (now 6-9 years of age) developed normally, the 4th patient (6 years old), however, presents with slight psychomotor disabilities. Early treatment of a patient with DHPR deficiency was highly unsatisfactory. This boy died at the age of 23 months.