A. T. Rundle

Serum IgD levels and infections in down's syndrome

Abstract The levels of serum IgD-globulins in 59 cases of Downs syndrome and 59 mentally retarded subjects were estimated by radial diffusion. The mean for the Downs syndrome was 7.8 mg/100 ml and the controls 2.8 mg/100 ml, a difference which is significant at P = 0.01. Serum A/G and serum alkaline phosphatase were estimated and related to the IgD levels in an attempt to assess whether the elevation of the IgD was due to increased infection rates in Downs syndrome, and both were found to correlate with the IgD levels significantly. For A/G v IgD, r = −0.36, and for serum alkaline phosphatase v IgD, r = 0.38. No significant correlations could be detected in the control group. This evidence is taken to suggest that the increase in infections in Downs syndrome is responsible for the increase in IgD levels, but whether there is a modification of the normal response remains to be investigated.

Red cell polymorphisms in Down's syndrome. Gene frequencies and phenotype associations

The phenotype frequencies of red cell phosphoglucomutase (PGT), acid phosphatase (ACP), adenylate kinase (AK), 6‐phosphogluconate dehydrogenase (PCD), adenosine deaminase (ADA), alanine aminotransferase (ALA), isocitric dehydrogenase (ICD) and glucose‐phosphate dehydrogenase (G‐6‐PD) and the ABO blood groups were investigated in a group of 256 subjects with Downs syndrome and 409 subjects with mental retardation but without chromosomal defects. The estimates and standard errors of the gene frequencies, deviations from the Hardy‐Weinberg law and between‐group comparisons by Haldanes log ratio test were determined.

Red cell adenylate kinase phenotypes in the affective disorders

SummaryThe red cell adenylate kinase (AK) phenotype was determined by starch gel electrophoresis in 96 adult Caucasian subjects with affective disorders (24 with bipolar illness and 72 with unipolar illness). The phenotype frequencies and the gene frequencies of the bipolar group closely resembled that of the control subjects (180 subjects drawn from the population of a large institution for the mentally retarded), the unipolar group however, showed a significant increase in the frequency of the AK2 allele.The significance of these results have been discussed in relation to the known genetic and biochemical findings in the affective disorders. It is suggested that the mechanism involved may be a reduction of the enzyme activity in the tissues of subjects with the AK 2:1 phenotype. This may present a selective disadvantage in the form of a decrease in control of energy metabolism in general, and control of adenine nucleotide levels in nervous tissue in particular.

Hepatitis associated antigen and the ABO locus in Down's syndrome.

The recent observation by Arndt‐Hansen et al. (1974) of increased frequency of blood group A over group O in blood donors positive for the hepatitis associated antigen has been investigated in Downs syndrome, in order to establish if this could account for the increased frequency of the antigen in that syndrome.

Leucine aminopeptidase isoenzyme changes after treatment with anticonvulsant drugs

Abstract The serum leucine aminopeptidase (LAP) isoenzymes were investigated in 86 control subjects, 94 subjects under treatment with phenobarbitone, 80 subjects under treatment with phenytoin either alone or with phenobarbitone, 27 mysoline-treated subjects and 106 untreated jaundiced subjects. Phenytoin and mysoline appear to increase the presence of the slower running zone described in phenothiazine-treated subjects by Beckman et al.6. A series of enzyme and other liver function tests were carried out in an attempt to ascertain whether the mechanism involved was one of microsomal damage or drug induction, but in this respect the results were inconclusive. The use of the LAP isoenzymes as an estimate of liver damage is shown to have little value, and simply reflects similar changes in the levels of serum γ-glutamyl transpeptidase but is much less sensitive.