Genetic basis of facial changes in Down syndrome

chromosomes - Researchers at UCL, the Francis Crick Institute and King's College London have shed light on the genetics underlying changes in the structure and shape of the face and head in a mouse model of Down syndrome. They found that having a third copy of the gene Dyrk1a and at least three other genes was responsible for changes in development that result in 'craniofacial dysmorphology', which shows up as shortened back-to-front length and widened diameter of the head. Down syndrome affects one in 800 live births and is known as a 'gene dosage disorder' - meaning that it involves changes in the number of copies of genes. People with Down syndrome have three copies of chromosome 21 instead of two. Having three copies of certain genes on this chromosome causes aspects typical of Down syndrome, but it's not yet known which genes are responsible. Using genetic engineering, teams led by Professor Elizabeth Fisher (UCL Queen Square Institute of Neurology) and Professor Victor Tybulewicz (the Francis Crick Institute), created mouse strains with duplications of three regions on mouse chromosome 16, which mimics having a third chromosome 21. The mice show lots of traits associated with Down syndrome, including changes in the shape of the face and skull.