Gender-specific differences in hair rare trace element content in children with Down's syndrome

The primary objective of the present study was to assess the levels of hair ultra-trace elements in patients with Down's syndrome and the potential gender effects. A total of 50 children with Down's syndrome (70% boys, 30% girls) aged 0 - 5 years and 50 age- and gender-matched neurotypical controls were enrolled in the present study. Proximal parts of hair strands (0.5 - 1 cm) were collected in a quantity of 0.05 - 0.1 g. Prior to analysis the samples were washed with acetone and distilled water and subjected to microwave digestion. The obtained data demonstrate that children with Down's syndrome are characterized by a significant more than 2-fold increase in hair Ag levels as compared to the healthy controls. In turn, hair Pt levels in Down's syndrome patients was 43% lower in comparison to the control values. Notably, hair Rb in patients with trisomy 21 had 63% higher hair Rb levels as compared to the respective control levels, although the difference was nearly significant. Further analysis revealed that the observed difference is gender-specific: hair Ag levels were significantly increased only in female examinees, whereas significantly lower hair Pt levels were observed only in boys with Down's syndrome. Although the clinical significance of the revealed associations is unclear, one can propose that altered rare element levels may be associated with impaired metal-binding protein levels in Down's syndrome.