New research suggests a surprising reason for Down syndrome: cells associated with aging
Around the world, Down syndrome affects about one in 700 babies. In the first few hours or days of embryonic growth, dividing cells are unable to separate chromosome pairs properly, leaving an additional copy. Scientists have known for over six decades that the extra copy of chromosome 21, which causes cognitive impairment in people with Down syndrome, is responsible. However, how this happens remains a mystery.
In recent years, scientists have used new RNA-sequencing techniques to study the cells of pairs of twins – one with Down Syndrome and one without – and found a strange pattern. Not only the genes on chromosome 21, but also other genes were cranked up in people with Down syndrome. Gene expression was a mess on every chromosome. There was something else going on.
Cell Stem Cell published a report on Thursday by a team at the Massachusetts Institute of Technology that they may have discovered a surprising culprit – senescent cell types, which are implicated in a number of diseases of ageing. It was a small, preliminary study. Some experts are waiting for it to be replicated with samples from more people before they accept its conclusions. They are still fascinating.