Some of the patients with dwarfism are caused by chromosomal deletion or abnormality, both Turner syndrome (Turner’s syndrome), specially selected some knowledge for science, thank you for your attention! 1. What is the most basic plate that makes up the human body? Cells are like the bricks that make up the human body, our organs and tissues have tens of thousands of such bricks, (such as heart, muscle, bone, kidney brain, liver, fat). Cells are able to transmit information that then tells an organ how to behave or achieve a function so that it can perform its particular job. So who in turn transmits the information to the cell that it needs to express? It is the chromosomes that are stored inside almost all cells and the genes that are carried on the chromosomes. With all this talk about chromosomes and genes, what exactly are they? How is Turner syndrome related to them? Let’s get to know them! 2. What are chromosomes? In 1883, W. Roux first observed filopodia in the nucleus of cells that could be colored by alkaline dyes. And then people called this filamentous body as chromosome (English: chromosome; Greek: chroma = color, soma = body), as the name implies, is the small body that can be stained. Chromosomes are composed of DNA, RNA and proteins, and their morphology and number are germline specific. In the interphase nucleus, they exist and function as chromatin filaments. When the cell grows up and matures, it divides into new cells, at which time the chromatin filaments are spiralized, folded and packed into chromosomes, which become microscopically visible vesicles with different shapes, and are the carriers of genes, the genetic material. 3. What do human chromosomes look like? In 1956, Zhuang Youxing and others clarified that each human cell has 46 chromosomes, and the 46 chromosomes are paired into 23 pairs according to their size and shape. These pairs of chromosomes, one from the mother and the other from the father. The first to 22 pairs of these chromosomes are called autosomes and are common to both sexes, while the 23rd pair is a pair of sex chromosomes, the X and Y chromosomes. A fertilized egg with one pair of X chromosomes develops into a female, while a person with one X chromosome and one Y chromosome develops into a male. Thus, the normal sex chromosome composition is XX for females and XY for males, and when the sex chromosomes are abnormal, a genetic disorder is formed. 4. What is the role of chromosomes? If you think of each chromosome as a book, then you can imagine that in each book there are instructions for each part of the body, such as what color your hair is. The pages of this book are like the smallest units of information for genes, on which a particular trait or characteristic of a person is recorded. Our 46 pairs of chromosomes cover about 25,000 genes we have, and the X chromosome covers about 1,400 genes. 5. What does the term “phenotype” in genetics mean? The term phenotype was introduced by Danish geneticist W.L. Johansen in 1911. It refers to the performance of an individual in various aspects of form and function, such as height, skin color, blood type, and even personality. It means the behavioral manifestations and the behavioral patterns that individuals have in their appearance. Phenotype involves things that we can see, such as eye color or height, things that we can observe, such as musical ability or things that we can measure, such as blood cholesterol. Phenotypes are not solely due to genetics and genetic decisions, but can also be influenced by the environment, such as the education you receive, your life experiences, the food you eat the medications you take, what you know or don’t know about the toxic things that enter your body, etc. 6. What is wrong with the chromosomes of people with Turner syndrome? All the chromosomes contained in each normal gamete, i.e. sperm or egg, of a diploid organism are called a chromosome group. For example, the chromosome group of a normal human gamete contains 22 + X or 22 + Y is called haploid. A fertilized egg is formed by the union of a sperm containing one chromosome group and an egg containing one chromosome group. Therefore, the fertilized egg develops into an individual with two chromosomes, called diploid. The normal female karyotype is 46,XX and must have all the genes of both X chromosomes for ovarian development, with the gene that prevents short stature and webbed neck located on the short arm of the X chromosome. During sex cell division, for some reason, the sex chromosomes do not separate and there is only one chromosome in the cell; or the short arm of the X chromosome is broken or lost during division. If the number or structure of sex chromosomes is abnormal, ovarian hypoplasia syndrome can occur, forming a clinical congenital gonadal hypoplasia or Turner syndrome. 7. What is the mosaicism of chromosomes? If a sex chromosome is lost during any period of embryonic development, only that cell is affected, a condition called mosaicism. When we complete a karyotype, we can see chromosomes in many cells and we will say 46, what percentage of XX and what percentage of 45X. For example, if we look for 30 cells (which is the usual number we analyze) and only 15 cells have 45X the rest are all 46XX we would say there are 50% haploid chromosomes, labeled 46,XX[15]/45X[15]. When mosaicism is caused by the loss of the X chromosome in a 46XY embryo, it results in a patient with a 45X/46XY chromosome karyotype. You may have heard of mixed gonadal hypoplasia, in which neither testes nor ovaries are present during fetal sex gland development, that is, very early in gonadal development, depending on the type of these chromosomes in the cell, and in the case where the majority of chromosomes in the body are 45X, the person will show the typical results of Turner syndrome. At this point the gonads will not develop as normal ovaries, but rather some bands of fibrous tissue. In girls carrying the 45X/46XY chromosome karyotype, it is recommended that the gonads be removed in order to stop gonadal cell tumors from developing. This also helps to stop further effects of androgens. 8. What is a chromosome test? Chromosome examination is performed by using peripheral blood under the action of cell growth stimulating factor – phytoagglutinin (PHA) at 37℃ for 72 hours to obtain a large number of dividing cells, and then adding colchicine to stop the dividing cells at the middle of division so that chromosomes can be observed; then swelling the cells by hypotonicity to reduce the mutual Finally, the cells were fixed on slides with methanol and glacial acetic acid, and the structure and number of chromosomes were observed under the microscope. The karyotype of normal males is 44 autosomes plus 2 sex chromosomes X and Y. It is often expressed as 46,XY in the examination report. Normal females have the same autosomes as males and 2 sex chromosomes XX, which are often expressed as 46, XX. 46 indicates the total number of chromosomes, and anything greater or less than 46 is considered an abnormal number of chromosomes. Missing sex chromosomes are often represented by O. 9.What are the ways we get chromosomes? The chromosomes are arranged in pairs and numbered from the largest to the smallest, from 1 to 22 respectively, and are called a karyotype. The karyotype can also be obtained from the amniotic fluid surrounding the developing fetus in utero or from a strip of skin cells from the mouth. The cells are then expanded at least 1250 times with a microscope to look at the chromosomes of the cells. 10. What are genes? A gene (genetic factor) is the material basis of heredity, a molecular fragment of DNA that has a genetic effect. Genes pass genetic information to the next generation through replication, causing the offspring to develop traits similar to those of their parents. There are about tens of thousands of genes in humans, which store all the information about the process of conception and growth of life and apoptosis. Through replication, expression and repair, they perform important physiological processes such as reproduction of life, cell division and protein synthesis. Figuratively speaking, genes are the code of life, recording and transmitting genetic information. All life phenomena, including illness and death of organisms, are related to genes. It also determines the intrinsic factors of human health and is closely related to human health. Scientists believe that by measuring each gene, people will be able to find new ways to treat and prevent many diseases, such as cancer and heart disease. 11. Do you understand how genes work? Genes are made up of DNA (deoxyribonucleic acid), a chemical used to give the necessary instructions to direct information and body functions. You may have heard of the genetic code, which are four chemicals (nucleotides) represented by the letters A, T, C, and G4, which are strung together in two long strands in each chromosome. An important property of DNA is that it acts as a template for copying itself, which is important because during cell division, an exact copy of each DNA molecule must be able to be passed on to the daughter cells. Chromosomes and genes are inherited from our parents and they form the basis for transferring the characteristics of the parents to the offspring. 12. What are the effects of a missing or defective gene on us? All of us have some genes missing (gene deletions) or defective (gene mutations), or even copies (gene duplications). Like a book, if a page is missing, a page is wrong, a page is in the wrong order or a page is duplicated, the reader may not be able to read or understand the wrong knowledge from the book. If a gene is wrong, it affects the protein, and when the protein is wrong, the whole person is affected. It can cause serious diseases like cancer, and it can also make you more likely to become overweight if you don’t eat scientifically or exercise well. Sometimes these errors come from our parents, in other words, they are present in the egg and sperm. Sometimes they occur before birth during the embryonic and fetal period, and sometimes they stay with us for the rest of our lives.