Chromosomal problems can lead to different genetic disorders. These issues happen because of changes in the number or shape of chromosomes. Let's break this down:

1. Numerical Abnormalities: This happens when a person has the wrong number of chromosomes.

   • Aneuploidy: This means there is an abnormal number of chromosomes. For example, Down syndrome happens when there is an extra chromosome 21 (called trisomy 21). It affects about 1 in every 700 babies born, which is around 0.14% of people.
   • Polyploidy: This means there are more than two complete sets of chromosomes. This usually isn't possible for humans and often leads to serious problems.

2. Structural Abnormalities: These involve changes in how chromosomes are built. These changes can include parts being lost, added, flipped, or swapped.

   • Deletions: This is when a part of the chromosome goes missing. This can lead to disorders like Cri du Chat syndrome, which affects about 1 in every 50,000 babies born.
   • Translocations: This is when a piece of one chromosome breaks off and sticks to a different chromosome. This can cause issues like Chronic Myeloid Leukemia (CML).

It’s really important to understand these chromosomal problems. They help doctors figure out hereditary conditions, build family trees, and think about the ethics of genetic testing and counseling since about 7.9% of people have genetic disorders.