Intellectual Disability

Intellectual disability (mental retardation).

Aneuploidy and Intellectual Disability

Aneuploidy is the presence of an abnormal number of chromosomes in cells. The gain or loss of a chromosome in germ cells is the most common cause of chromosomal aneuploidy. Trisomy 21, trisomy 18, and trisomy 13 are characterized by congenital anomalies with intellectual disability (ID) or short lives. Recently, mosaic variegated aneuploidy (the presence of a different number of chromosomes in ...

Chapter 5: Intellectual disability

Pragmatic language skills are often impacted in individuals with intellectual disability, a developmental condition defined by deficits in intellectual and adaptive skills. In this chapter, we review the literature on pragmatic language in three genetically-based causes of intellectual disability – Down syndrome, fragile X syndrome, and Williams syndrome. We focus on groupcomparison studies of ...

Inv21p12q22del21q22 and intellectual disability.

Chromosomal rearrangements are common in humans. Pericentric inversions are among the most frequent aberrations (1-2%). Most inversions are balanced and do not cause problems in carriers unless one of the breakpoints disrupts important functional genes, has near submicroscopic copy number variants or hosts "cryptic" complex chromosomal rearrangements. Pericentric inversions can lead to imbalanc...

Molecular Genetics of Intellectual Disability

The goal of this chapter is to review the current knowledge of the genetic causes of intellectual disability, focusing on alterations at the chromosomal and single gene level, with particular mention to the new technological developments, including array technologies and next-generation sequencing, which allowed an enormous increase in yield from genetic studies. The cellular and physiological ...