The putative role of HMG-14 in the structure of active chromatin raises the possibility that elevated levels of this protein may be a contributing factor in the etiology of Down syndrome.
Apart from a reduced number of T lymphocytes (CD3+) in DS children and of B lymphocytes (CD19+) in both DS groups, the major alteration we found was a marked age-related increase of the percentage of cells bearing markers associated with NK activity, such as CD16, CD56, and CD57.
Apart from a reduced number of T lymphocytes (CD3+) in DS children and of B lymphocytes (CD19+) in both DS groups, the major alteration we found was a marked age-related increase of the percentage of cells bearing markers associated with NK activity, such as CD16, CD56, and CD57.
A speculative hypothesis about a gene dosage effect of Cu/Zn-superoxide dismutase in preventing toxic radical formation in the substantia nigra of DS patients is presented.
Transcriptional regulation of the gene encoding the amyloid precursor protein (APP) may play an important role in the formation of the amyloid depositions observed in Alzheimer disease and Down syndrome patients.
The amyloid precursor protein (APP) is thought to be processed aberrantly to yield the major constituent of the amyloid plaques observed in the brains of patients with Alzheimer disease and Down syndrome.
A blind study was set up to examine the in vitro growth characteristics of skin fibroblasts from 2 individuals with and 9 at risk for familial Alzheimer disease, 4 individuals with sporadic Alzheimer disease, 18 with Down syndrome as well as 5 younger and 6 older controls.
Cu,Zn superoxide dismutase (SOD-1) and glutathione peroxidase (GSHPx) activities were significantly elevated (1.39-fold and 1.24-fold, respectively) in DS individuals without AD.
The mean catalase (CAT) activity was no different in DS and control individuals; however, in a paired regression analysis, DS patients without AD had marginally lower CAT activity than control individuals, whereas DS patients with AD had slightly but not significantly higher CAT activity.
This raises the possibility that abnormalities in S100 protein gene dosage at a critical period during development may be responsible for some of the neurologic abnormalities associated with DS.
This raises the possibility that abnormalities in S100 protein gene dosage at a critical period during development may be responsible for some of the neurologic abnormalities associated with DS.
The localization of the Alzheimer amyloid protein precursor (APP) gene on chromosome 21, along with its overexpression in Down's syndrome brain compared with normal brain, suggests that alterations in APP gene expression may play a role in the development of the neuropathology common to the two diseases.
Fetal weight does not seem to account for the lower maternal serum alpha-fetoprotein levels seen in fetuses with Down syndrome but may partially account for the lower levels seen in fetuses with trisomy 18.