Robertsonian translocation is a common form of chromosomal rearrangement that occurs in the five acrocentric human chromosome pairs, namely 13, 14, 15, 21, an 22. They are named after the American insect geneticist W. R. B. Robertson, who first described a Robertsonian translocation in grasshoppers in 1916. They are also called whole-arm translocations or centric-fusion translocations. They are a type of chromosomal translocation.