Genes for Down syndrome and Alzheimer disease share the same chromosome 21

Parkin is downregulated among autophagy-related proteins prior to hyperphosphorylation of Tau in TS65DN mice

Autophagy is a pathway through which cells execute a plethora of functions, such as macromolecules and organelles quality control, recycling of building blocks and apoptosis. Numerous studies have shown in the past that autophagy is an important mechanism associated with the pathology of various neurodegenerative diseases, whose impairment may lead to several disease-characteristic phenotypes (e.g. misfolded protein and defective organelles accumulation). With this in mind, we aimed to investigate whether alterations in expression of autophagy-related proteins would show before hyperphosphorylation of Tau, a hallmark of Alzheimer's disease (AD). After analyzing 7 different proteins, we observed that, while Pink1 and p62 show an age-related reduction in the Ts65Dn mice respectively in the locus coeruleus and hippocampus, Parkin shows an age-genotype interaction-associated reduction in both brain areas. This suggests potential outcomes in pathways associated with Parkin that could relate to later stages of the disease development.

Plasma carnitine levels in children with Down syndrome

Carnitine is responsible for several chemical processes, including lipid metabolism, nerve cell conduction, reduction in muscle hypotonia, and limitation in oxidative damage to cells. In patients with Down syndrome (DS), the process of growth is behind that of normal children and neuromuscular control is attained somewhat later. The purpose of this study was to assess variation in levels of carnitine in normal and DS children and the relationship between the amount of carnitine and age. The study involved 30 (15 girls, 15 boys) normal children and 40 (20 girls, 20 boys) DS patients of Turkish ancestry, 6 months to 13 years of age. Carnitine level was determined using Deufel's enzymatic method. Carnitine level was significantly lower in DS patients compared with normal children between 6 months to 5 years of age. Between 5 and 13 years of age, the level of carnitine was about the same in both the normal and DS groups. The results suggest that carnitine level shows a different pattern of age related increase in DS compared to normal children.