[Prenatal brain damage in maternal, untreated phenylketonuria].

Several reports in literature exist about mentally retarded non-phenylketonuric offspring from untreated phenylketonuric mothers with normal intelligence. One additional case is added who was detected after screening of about 1600 pregnant women. Biochemical investigations of the mother identified her as "classical phenylketonuria". Column chromatographic analysis of amino acids in amniotic fluid revealed a very high pheylalanine level and the diminution of the other, especially essential amino acids. The estimated amino acids in fetal brain also revealed a very high phenylalanine level. Routine screening for phenylketonuria by means of the Guthrie's test is recommended for all pregnant women at the first visit of the counseling.