Chromosome abnormalities of the developing baby (foetus) are uncommon, but many parents are concerned their baby might be affected.
Several tests are now available to screen for and diagnose these abnormalities at an early stage of the pregnancy.
What are chromosomes
- Chromosomes are the thread-like structures present within the central part (nucleus) of living cells.
- Chromosomes are composed of DNA (deoxyribonucleic acid) and therefore are the physical form in which our genes exist.
- Humans have a total of 46 chromosomes. Two of these are the sex chromosomes, which are called X and Y.
- The composition of the chromosomes for females is 46XX, while for males it is 46XY. Each half of the pair of chromosomes is inherited from each parent.
- Chromosomes are like library shelves - each houses a large number of books, which are the individual genes.