What are chromosomal abnormalities?

Chromosomal abnormalities are shortcomings in the structure or number of chromosomes. Depending on the nature of abnormalities, such abnormalities may be incompatible with life, in which case the child will spontaneously interrupted in the early stages of pregnancy, or can be almost imperceptible, sometimes it does not appear until someone undergoes routine medical testing for something like an adult. It is estimated that approximately one of every 150 children has a form of chromosomal abnormalities.

There are two main types of chromosomal abnormalities. The first are structural abnormalities, which means that the structure of individual chromosomes is somehow damaged or mixed. The second is numerical abnormalities. A normal child has 46 chromosomes created with two sets of 23 chromosomes inherited from parents and an unusual number of chromosomes can lead to serious congenital defects. The medical term for numerical abnormality is "aneuploids".

Many chromosomal abnormalities Occur during fetal development because something spoiledIt is when the cells are duplicated. In the early stages of fetal development, cell duplication takes place at incredibly fast speed, which means there are many opportunities for replication errors. When chromosomal abnormalities develop after such fertilization, they usually lead to a mosaic in which some cells have abnormality, and others do not.

Chromosomal abnormality can also occur before fertilization. If an error occurs during egg replication and sperm cells, this may result in chromosomal abnormality, if the cell becomes part of a zygota, a fertilized egg that has the potential to develop into the fetus. As the cells in Zygot replicate, chromosomal abnormality is replicated with them.

Errors in the structure include: deletion, duplication, inversion, advertising and translocation. All forms of chromosomal scratching result in a certain form. Either a part of the chromosome is missing, duplicated, inverted, added there, tode nepatří, nebo je zaměněna na jinou část chromozomu. V závislosti na sekci a postiženém chromozomu mohou takové abnormality generovat závažné vrozené vady nebo projít bez povšimnutí. Aneuploidie může mít podobu trizomie, ve které má pár chromozomů připevněný extra chromozom nebo monosomii, ve které chybí polovina páru chromozomů.

Obecně platí, že chromozomální abnormality nejsou zděděny, protože během buněčné duplikace vyplývají z chyb. Riziko chromozomálních abnormalit se zvyšuje s věkem, což je jeden z důvodů, proč se pro starší matky doporučuje rozsáhlé prenatální testování. Děje se však také u mladších žen a mnoho potratů je výsledkem chromozomálních abnormalit. V případě, že dítě nebo plod je diagnostikován s chromozomálními abnormalitami, je k dispozici řada možností,a situaci lze diskutovat s genetickým poradcem.