Chromosomal protein HMG-14 gene maps to the Down syndrome region of human chromosome 21 and is overexpressed in mouse trisomy 16.

Abstract

The gene for human high-mobility-group (HMG) chromosomal protein HMG-14 is located in region 21q22.3, a region associated with the pathogenesis of Down syndrome, one of the most prevalent human birth defects. The expression of this gene is analyzed in mouse embryos that are trisomic in chromosome 16 and are considered to be an animal model for Down syndrome. RNA blot-hybridization analysis and detailed analysis of HMG-14 protein levels indicate that mouse trisomy 16 embryos have approximately 1.5 times more HMG-14 mRNA and protein than their normal littermates, suggesting a direct gene dosage effect. The HMG-14 gene may be an additional marker for the Down syndrome. Chromosomal protein HMG-14 is a nucleosomal binding protein that may confer distinct properties to the chromatin structure of transcriptionally active genes and therefore may be a contributing factor in the etiology of the syndrome.