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Robertsonian Translocations
In Robertsonian translocations, the centromeres of two (homologous or nonhomologous) acrocentric chromosomes (chromosomes #13, 14, 15, 21 and 22, in which the centromeres are close to one end of the chromosome) appear to fuse to form a single chromosome containing the long arms of each of the reattached chromosomes. These individuals have a total of only 45 chromosomes rather than the normal 46 chromosomes per cell. Loss of the small variable regions of these acrocentric chromosomes may not lead to detectable abnormalities, since they appear to contain few genes. This illustration shows how a 14/21 Robertsonian translocation may occur. | |||||||||||||
