Translokatsioon

Translokatsioon (translocation) is a chromosomal rearrangement in which segments of DNA are relocated between non-homologous chromosomes or within a chromosome. The main forms are reciprocal translocation, Robertsonian translocation, and non-reciprocal translocation. In reciprocal translocations, segments are exchanged between two chromosomes, often preserving the total amount of genetic material (balanced translocation). Robertsonian translocations involve fusion of two acrocentric chromosomes and loss of their short arms, producing a single chromosome. Non-reciprocal translocations transfer genetic material in one direction, with potential content loss on the recipient chromosome.

Effects of translokatsioon can vary. Balanced translocations may be inherited or occur de novo and are often asymptomatic, but can cause infertility, miscarriages, or congenital anomalies in offspring due to the creation of unbalanced gametes during meiosis. Unbalanced translocations lead to duplications or deletions of chromosomal segments and typically have phenotypic consequences, including developmental disorders or medical conditions.

Detection and significance: Translokatsioonid are identified primarily through cytogenetic methods. Karyotyping can reveal large rearrangements; fluorescence in situ hybridization (FISH) targets specific chromosome regions; array comparative genomic hybridization (array-CGH) and sequencing-based approaches offer higher resolution. Clinically, translokatsioon on reproductive genetics and oncology. Somatic translocations can create fusion genes that drive cancer, such as t(9;22) BCR-ABL in chronic myeloid leukemia, t(15;17) PML-RARA in acute promyelocytic leukemia, and t(8;14) IGH-MYC in Burkitt lymphoma.