Abstract

In human beings, dicentric chromosomes are occasionally encountered as stable
chromosomal constitution except Robertsonian translocations that occur in an
insignificant portion of the population. In present investigation, an 18 years female born to
younger parents, who was naturally delivered but was under wt. after birth and had 42, XX,
tdic (2; 21) chromosomal constitution is described. It is suggested that the stability of
dicentric chromosome has been attributed to inactivation of chromosome no. 2 centromere.
Stanford-Binet test was performed to ascertain the degree of intellectual disability and was
found to be severe (IQ: 20-25 to 35-40). A reciprocal translocation which leads to dicentric
chromosome formed from a chromosome 2 and a 21chromosome has not apparently been
reported in individuals with intellectual disabilities.