“…Protein estimations on sera from patients with Down's syndrome have shown lower albumin and Iiigher gamnia-glolmtin levels than sera from otlier groups of mentally retarded children (Stern and Lewis, 1957;Sobel, Strazzulla, Sherman, Elkan, Morgenstein, Marius and Miesel, 1958;Skanse and Laurell, 1962;Prithani, Appleton and Fluck, 1963). More recently, various investigators have measured immunoglobulins by radial immunodifFusion in patients witli Down's syndrome with varying findings.…”