Intellectual disability (ID) is one of the most common disabilities worldwide, affecting nearly 2% of the global population. Here we examined patients from eight families suffering from a form of ID that is coupled with squint of the eye, and in each case found the same DNA mutation, in a gene called ADAT3. This gene is part of a sub-machinery vital for correctly converting DNA into protein within the cell, and excitingly this is the first time that a human mutation has been uncovered in this particular sub-machinery. Although mutations in a large number of genes lead to general ID, focusing on ID that contains a second defining feature (in this case, squint) appears to result in more focused genetic findings. (By Dr. Fowzan S Alkuraya, http://jmg.bmj.com/content/early/2013/04/24/jmedgenet-2012-101378 )