Isochromosomes

Isochromosomes are created by the incorrect division of the centromere.
 * Normally centromere divides vertically. In this case it divides horizontally.
 * The result is usually the lost of one arm. It means that newly created chormosome has just two long arms or two short arms which are connected normally at the centromere.
 * We can find it on X chromosome very often.
 * It is a huge problem during fertilization. Because fetus then get a trisomy for one arm and a monosomy for the second arm.

Related articles

 * Chromosome abnormalities