Diagnostic exome sequencing in persons with severe intellectual disability
Original research article by J. de Ligt et al. (2012).
Read the article here.
The researchers performed exome sequencing on 100 people with severe intellectual disability and their parents who did not have the disability. The goal of the study was to identify a genetic cause for the diagnosis of intellectual disability. In 765 additional people with intellectual disability, the researchers performed further analysis on five genes that have been associated with intellectual disability—CTNNB1 and also DYNC1H1, GATAD2B, ASH11, and KIFSC.
Three people were found to have changes in CTNNB1. Two of them had changes that were de novo (not inherited from either parent. The third person’s inheritance was unknown, because the parents were not available to test. All three people had severe intellectual disability, absent or very limited speech, smaller-than-average head size, and tight muscle tone, which limited their ability to walk. The researchers noted that exome sequencing resulted in diagnoses in about 16% of the people in their sample.