Correlative study of radioreceptor assay and radioimmunoassay of serum growth hormone in children. II: Primary, genetic and intra-uterine growth retardation

Growth hormone (GH) was measured by radioreceptorassay (RRA) and radioimmunoassay (RIA) in the sera of 24 children with idiopathic primary growth retardation (PGR), 15 with genetic short stature (GSS) and 11 with intra-uterine growth retardation (IUGR), and compared to results obtained in normal children. The average RRA/RIA ratio was close to normal in PGR (1.02 +/- 0.05) and in IUGR (1.06 +/- 0.07), and slightly though not significantly lower in GSS (0.86 +/- 0.06). Some variability in RRA/RIA ratio was found in individual patients of each group, and some sera gave a non-parallel displacement of the tracer when compared to the standard curve. But no genetic difference of RRA-assayable GH was found between the three groups studied and normal children.