TY - JOUR T1 - Carphology by A Fo Ben JF - Practical Neurology JO - Pract Neurol SP - 86 LP - 86 DO - 10.1136/practneurol-2014-001061 VL - 15 IS - 1 A2 - , Y1 - 2015/02/01 UR - http://pn.bmj.com/content/15/1/86.abstract N2 - Rare genetic disorders pose a conundrum to the clinician—it can be tricky to know where to start when commissioning gene tests. An international consortium performed exome sequencing on 84 individuals with progressive myoclonus epilepsy; a third of cases showed mutations likely to be causative in known genes. More interestingly, a further 11 unrelated people had the same de novo mutation (p.Arg320His) in KCNC1—which had not previously been linked to epilepsy. De novo mutations are interesting here as the symptoms were relatively late-onset and because the progressive myoclonus epilepsies were conceptualised as mostly recessive. The ‘diagnostic exome’ when it comes to a lab near you may help to illuminate these rare but important diagnoses. Nat Genet 2014. doi:10.1038/ng.3144 Why some people are more likely develop a cognitive impairment than … ER -