Balanced chromosomal rearrangements represent one of the most common forms of genetic abnormality affecting approximately 1 in every 500 (0.2%) individuals. Difficulties processing the abnormal chromosomes during meiosis lead to an elevated risk of chromosomally abnormal gametes, resulting in high rates of miscarriage and/or children with congenital abnormalities. It has also been suggested tha...

Half of all vertebrate species share a series of chromosome fusions that preceded the teleost genome duplication (TGD), but we do not understand the causative evolutionary mechanisms. The "Robertsonian-translocation hypothesis" suggests a regular fusion of each ancestral acro- or telocentric chromosome to just one other by centromere fusions, thus halving the karyotype. An alternative "genome-s...

CONTEXT Robertsonian translocations (RT) are among the most common balanced structural rearrangements in humans and comprise complete chromatin fusion of the long arm of two acrocentric chromosomes. Nevertheless, non-Robertsonian translocation involving these chromosomes is a rare event. CASE REPORT We report a de novo unbalanced translocation involving chromosomes 15 and 21. The newborn was ...

Chromosomal polymorphisms (CPM) are minor variation of karyotype, found in >1% the general population. Heterochromatin, inactive part chromosome, shows frequent polymorphism - increase/decrease length. Recently, studies show that heterochromatin is not inert, but contains genes essential for spindle attachment, chromosome movement, meiotic pairing, and sister chromatid cohesion. Balance...