NGS improves the diagnosis of x-linked intellectual disability (XLID)

Abstract

X-linked intellectual disability (XLID) is considered to be a collection of conditions that are each caused by mutation in one of the many X-linked genes associated with either a syndromic or nonsyndromic form of intellectual disability. A significant number of XLID conditions have been described, but only approximately 50 % of the causative XLID genes have been discovered. For affected individuals from families with clear or potentially X-linked inheritance, the strategy for next-generation sequencing (NGS) can be tailored appropriately, given the ability to focus sole attention on the X chromosome rather than the entire genome. The primary goal of this chapter is to focus on the principles associated with testing known XLID genes that have been included on various targeted NGS panels. These principles can be extended to other X-linked genes that may be implicated in XLID, as well as to other genes on the X chromosome with relevant medical implications.