Expanding our testing for intellectual disability (ID), the University of Chicago Genetic Services Introduces New Expanded Next Generation Sequencing Panels for Non-specific ID.

Genetic testing for non-syndromic intellectual disability (NSID) presents challenges in daily clinical practice.  Historically focusing on genes on the X-chromosome, recent research has brought attention to the growing contribution of autosomal genes in the genetic elucidation of NSID. Utilizing exome sequencing for novel gene discovery, recent studies have estimated the prevalence of autosomal de-novo mutations to range from 16% to 55% (1,2). While autosomal recessive ID is rarer, estimates of contribution of recessive mutations to ID is considered to be as high as 25%, typically characterized in consanguineous families (3). 

In addition, the distinction between syndromic and non-syndromic ID is not precise.  Conditions previously regarded as non-syndromic forms of ID may have additional clinical findings that were not intially recognized or emphasized, thus a range of mutations in a single gene can sometimes confer both syndromic and non-syndromic phenotypes.  Our ‘non-specific’ ID panels include primarily non-syndromic forms of ID, but also includes several more syndromic forms of ID to account for the above'  

Since 2012, UCGS has been offering several next generation sequencing panels for non-specific ID  including an Autosomal Recessive panel, a X-linked panel and a Comprehensive (including X-linked, autosomal recessive and autosomal dominant genes) panel.  To date, we have identified pathogenic sequence changes in 19% of patient samples we've received.  The majority of mutations identified have been in autosomal genes. 

We are now pleased to announce expanded non-specific ID panels.

Our Autosomal Recessive Non-Specific ID panel now includes 36 genes.

Our X-linked Non-Specific ID panel now includes 75 genes. 

Our Comprehensive Non-Specific ID panel now includes 144 genes


(1)Rauch A, Wieczorek D, Graf E et al: Range of genetic mutations associated with severe non-syndromic sporadic intellectual disability: an exome sequencing study. Lancet 2012; 380: 167; (2) de Ligt J, Willemsen MH, van Bon BW et al: Diagnostic exome sequencing in persons with severe intellectual disability. N Engl J Med 2012; 367: 192-1929; (3)Schuurs-Hoeijmakers JH, Vulto-van Silfhout AT, Vissers LE et al: Identification of pathogenic gene variants in small families with intellectually disabled siblings by exome sequencing. J Med Genet 2013; 50: 802-811.