Somatic and gametic chromosomal aberrations

Chromosomal aberrations are numerical or structural deviations from the normal sturcture of the karytoype.

Somatic chromosomal aberrations

 * it is not passed on to offspring
 * in the early stages of the development of the zygote - a mosaic occurs, syndromes similar to gametic chromosomal aberrations occur
 * postnatally, they usually mean the formation of tumors
 * numerical and structural aberrations
 * for example, the Philadelphia chromosome – t(9;22) in CML, translocation t(8;14) in Burkitt's lymphoma, etc.

Gametic chromosomal aberrations

 * it is passed on to offspring
 * numerical


 * 1) nondisjunction in meiosis I results in a gamete with 2 different (one from the father, one from the mother) or none of the pair of chromosomes in which the nondisjunction took place
 * 2) nondisjunction in meiosis II results in a gamete with 2 identical (both from the father or the mother) or none of the pairs of chromosomes in which nondisjunction occurred
 * 3) polyploidy – it is the multiplication of entire sets of chromosomes, genomic aberrations (hydatiform moles arise, incompatible with life)
 * 4) aneuploidy – trisomy (Down syndrome, Patau syndrome, Edwards syndrome, Klinefelter syndrome, XXX syndrome, XYY syndrome) or monosomy (Turner's syndrome)


 * structural


 * 1) deletion (deletion syndromes: Cri du chat syndrome (5th chromosome), deletion form of Turner syndrome; microdeletion syndromes: Wolf-Hirschhorn syndrome (4th chromosome), Prader-Willi and Angelman syndrome (15th chromosome), DiGeorge syndrome, etc.) – terminal and interstitial deletion
 * 2) duplication
 * 3) insertion
 * 4) inversion
 * 5) ring chromosome
 * 6) chromosome marker
 * 7) dicentric chromosome
 * 8) translocation – reciprocal and Robertsonian
 * 9) isochromosome

Related Articles

 * Chromosomal abnormalities
 * Numerical chromosomal abnormalities
 * Structural chromosomal abnormalities
 * Chromosomal aberrations in the ethiology of neoplasia