Biomedical subjects
Publications and source records attributed to A M Monk.
We report a child with classical galactosaemia whose diagnosis was missed until 12 weeks of age. The limitations of urine screening tests are discussed and the wider use of a qualitative enzyme assay for screening is recommended. Reference ranges for a quantitative enzyme assay using 14galacoste-1-phosphate as substrate are presented.
A method to measure the enzyme galactose-1-phosphate uridyltransferase in cultured cells is described. The optimun pH was 8.7 and no enzyme activity was found without preincubation with dithiothreitol. The KM values for Gal-1-P and UDPG for the wild type enzyme were found to be 0.2 mM and 0.08 mM, respectively. Values for the Duarte variant were found to be identical. No significant change in enzyme activity with time after subculture was found in either cultured skin fibroblasts or cultured amniotic fluid cells. Different transferase genotypes were clearly distinguished and reference range established. Transferase levels found in normal cultured amniotic fluid cells were the same as in normal cultured skin fibroblasts. The results of a prenatal diagnosis was obtained within 3 weeks of amniocentesis.
A radioimmunoassay for alpha-fetoprotein (AFP) is described and normal ranges for both maternal serum and in amniotic fluid throughout pregnancy are defined. Maternal serum AFP levels in at risk pregnancies were found to be no different from those in normal pregnancies. AFP levels in pregnancies complicated by neural tube and other congenital defects, fetal death or maternal hypertension are documented. Eight patients with a fetus deformed by anencephaly or an open spina bifida were tested before 22 weeks; seven of them had raised serum AFP levels. Other causes of raised serum AFP levels are described and the significance of a raised serum AFP level is discussed with particular reference to screening programmes.