How to read chromosomes

As we all know, every person is a living being produced by the combination of chromosomes from male and female bodies. When a man's sperm enters a woman's vagina and combines with her egg, there is a high chance that an embryo will be produced, which is the basis of human reproduction. However, chromosomes are a very large system with many interesting phenomena that dominate human reproduction. So how should we view chromosomes?

Every human individual begins as a fertilized egg cell, and through continuous cell division to reach trillions of cells, it forms a complete individual.

Therefore, the formation of the first cell of a human being, the fertilized egg cell, is very important. If the chromosomes of the first cell are abnormal, it will affect the subsequent cell division process, and eventually cause abnormal development of the embryo or fetus.

Since each cell nucleus that makes up our human body carries the same chromosomes as the initial fertilized egg cell, as long as there are a person's cells or tissues, his chromosomes can be found.

Currently, we can use various technologies to observe and analyze our chromosomes and genes, that is, to examine our genetic material.

Our karyotype reports come with complete karyotype images and descriptions. The most important thing for us is to understand the results in the "Chromosome Karyotype" column. The most important thing for a chromosome report is the chromosome karyotype conclusion. For ease of understanding, we roughly divide the chromosome karyotype results into three types.

1. Normal chromosome karyotype

The normal male chromosome karyotype is: 46, XY

The normal female chromosome karyotype is: 46, XX

If your chromosome report shows the above two karyotypes and your gender matches the chromosome karyotype, then your chromosomes are completely normal.

2. Chromosome variation (chromosome polymorphism)

Chromosome variation is also often referred to as chromosome polymorphism. The total frequency of various chromosomal mutations in the population is approximately 10%-15%. Although chromosomal variations appear to be different from the normal karyotype, they have no actual clinical significance. Therefore, chromosomal mutations can be regarded as normal chromosomes. They are harmless to personal health and will not affect the reproduction of offspring.

Chromosome variations can be divided into many categories, the most common of which are variations in heterochromatin length and position, as well as variations in satellite and satellite stalk regions. The reports you may see often look something like this:

46, XY, 9qh+

46, XX, 21pstk+

46, XY, inv(9)(p11q12)

46, XY, Yqh+

The above are just some examples. In fact, there are many forms of chromosome mutations. The easiest way to know whether your chromosomes are mutant chromosomes is to check whether there is a "chromosome polymorphism" judgment in the result description of our report. If your karyotype is "polymorphic", then you can rest assured that it is equivalent to normal chromosomes.