De novo mutations in severe intellectual disability

Diagnostic exome sequencing. Severe intellectual disability (ID) is unexplained in the vast majority of patients and is thought to be genetic. The genetics of intellectual disability has traditionally focused on the X chromosome, where more than 100 possibly causative genes for ID are located. But other, autosomal genes are also found in large number of cases. A recent study in the New England Journal of Medicine now reports on trio exome sequencing in patients with unexplained severe intellectual disability. The authors identify causative de novo events in a large proportion of patients. Interestingly, more than half of their patients had epilepsy. Continue reading