mRNA

Very small segments of genes called “microexons” influence how proteins interact with each other in the nervous system, scientists at the University of Toronto have found, opening up a new line of research into the cause of autism.

Damage to DNA is an issue for all cells, particularly in cancer, where the mechanisms that repair damage typically fail. The same agents that damage DNA also damage its sister molecule messenger RNA (mRNA), which ferries transcripts of the genes to the tens of thousands of ribosomes in each cell. But little attention has been paid to this damage.

Susan Brooks had reached a dead end.

Brooks, a medical geneticist at Rutgers Robert Wood Johnson Medical School, was trying to diagnose a boy who had a genetic disorder she had never encountered before. The young patient showed delayed development, microcephaly, recurrent febrile illnesses, seizures, overall slow growth, and several minor craniofacial and limb malformations.

Neurons are electrically charged cells in the nervous system that interpret and transmit information using electrical and chemical signals. A neuron’s electrical charge is determined by the flow of ions – charged atoms – in and out of the cell through pores, called ion channels. These pores open, allowing ions to rush in, and then shut. The neuron becomes charged and “sparks” the next neuron in line.