Since the majority of the patients had a normal alpha-1-antitrypsin phenotype, the results of this study indicate that a deficiency in alpha-1-antitrypsin plays no role in the respiratory fragility of individuals with Down's syndrome.
Using this material it was demonstrated that the anomalous Hp inheritance in Down's syndrome was not due simply to an increase in maternal age when the children were born.
The mentally retarded patients have a higher mean pseudocholinesterase activity than those with Down's syndrome who, in turn, have activity than the healthy controls.
A child with characteristic clinical features of Down's syndrome and raised red cell SOD-1 activity was found to have, in addition to a single chromosome 21, a reverse dicentric tandem translocation of two No 21s with dual NORs and C band regions.
Because both IfRec and SOD-1 map to mouse chromosome 16, it will now be possible to use mice trisomic for this chromosome to determine whether certain aspects of the Down syndrome phenotype in man are caused by an altered dosage of IfRec and SOD-1.
The mean alpha 2-macroglobulin concentrations were investigated and it was shown that PiMZ phenotypes had a higher concentration, 2.67 +/- 0.27 g/l (newborns) and 2.74 +/- 0.32 g/l (Down's syndrome), in comparison with PiMS, PiSS, and PiMM.
Assessment of the alpha 1-antitrypsin/alpha 1-protease inhibitor (PI) types in these DS children revealed a significantly higher value of non-M PI variants (P less than 0.05).
The CPE model had been considered but rejected by Penrose, who preferred models postulating changes with age assuming either a power function X10, where X is age or a Poisson model in which accumulation of 17 events was the assumed threshold for the occurrence of Down's syndrome.
The gene locus for human cytoplasmic superoxide dismutase (SOD-1; superoxide:superoxide oxidoreductase, EC 1.15.1.1) is located in or near a region of chromosome 21 known to be involved in Down syndrome.
Seasonal periodicity of the prolactin concentration in women and "transient hyperprolactinaemia", shown to be allied to delayed ovulation, may be related to these seasonal DS conception clusters.
This human prion gene has been mapped to human chromosome 20, negating a direct link between the prion protein and Down's syndrome or the amyloid of Alzheimer's disease.
These results indicate that the Down syndrome phenotype of this patient is due to microduplication of a chromosome 21 fragment containing the CuZn SOD gene.