What are the common chromosomal structural abnormalities?

What are the common chromosomal structural abnormalities? The basis of chromosomal structural abnormalities is chromosomal breakage. Experts point out that if the break heals immediately, no abnormality occurs, and if the fracture is recombined, it will lead to chromosomal abnormalities, so what are the common chromosomal structural abnormalities?

Common chromosomal structural abnormalities are: 1. Chromosome inversion: When there are two or more breaks in two or more chromosomes, the broken ends are reversed and then rejoined, resulting in the rearrangement of chromosomes, and the genetic sequence is also reversed, which is called chromosome inversion.

According to the occurrence location of the two fracture points, it can be divided into intra-arm inversion and inter-arm inversion. 2. Circular chromosome: refers to a break on the distal side of the long and short arms of a chromosome, and the two ends of the filromere are connected to each other to form a ring, and this derived chromosome is called a circular chromosome, and it will be lost after no centromere fragment.

3. Chromosome deletion: A part of a chromosome arm is missing, which is called deletion. When a chromosome is broken, a portion of the chromosome can be lost, resulting in the formation of a chromosome deletion.

Deletions can occur at the end or in the middle of a chromosome. 4. Chromosome recurrence: A part of the chromosome is duplicated, and the newly copied segment of the chromosome can be located within the same chromosome, or attached to another chromosome, or become a separate segment.

If the zonal order of the repetitive segment is consistent with the original direction, it is called positive repetition, and if it is opposite to the original, it is called inverted repetition. 5. Chromosomal translocation: After two non-homologous chromosomes are broken, the broken parts are exchanged with each other and glued together, resulting in a rearrangement between chromosomes, which is called translocation.

According to the composition of the genetic material, it can be divided into balanced translocation (although the morphological size or number of chromosomes is different from normal after translocation, the genetic material in the cell is basically unchanged) and unbalanced translocation (the total number of chromosomes does not change, 2n = 46, but the genetic material increases, such as translocation type 21-trisomy). Robertsonian transposed centromere chromosomes break at or near centromere locations and then fuse at their near centromere to form a single new double centromere chromosome, which is also classified as a balanced translocation. For the question "What are the common chromosomal structural abnormalities?"

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What are the signs of sex chromosome abnormalities.

Answer] :d DNA and protein cross-linking is a function between DNA and protein, but it does not affect the structural abnormalities in the chromosome ridge. Abnormalities in spindle structure and function often cause changes in the chromosome set, but have no effect on chromosome structure; Base abnormalities in the DNA strand affect the information carried by the genes, but have no effect on the chromosome structure; DNA strand breaks and in situ reconnection also had no effect on the chromosome structure of Jingyin; Only when DNA strand breaks occur and ectopic reassignment occurs, chromosomal structural abnormalities can be caused.

The causes of chromosome structural variation include physical factors, chemical factors, biological factors, maternal age effects, etc. The types of variation in chromosome structure are deletions, deletions of a certain segment of a chromosome; Adding, chromosomes add a certain segment; Inversion, a segment of the chromosome is reversed by 180°; Translocation, the transfer of one segment of a chromosome to another non-homologous chromosome. The causes of chromosome structural variation include physical factors, chemical factors, biological factors, maternal age effects, etc.

The types of variation in chromosome structure are deletions, deletions of a certain segment of a chromosome; Adding, chromosomes add a certain segment; Inversion, a segment of the chromosome is reversed by 180°; Translocation, the transfer of one segment of a chromosome to another non-homologous chromosome.

Miscarriages, stillbirths, and malformations caused by chromosomal abnormalities are easy to occur, and even if a child is born, the offspring may still have abnormal chromosomes, and the offspring will have the same troubles as the previous generation when they reach childbearing age, and the problems caused by such genetic defects cannot be solved by taking medicine.

Common diseases include Down syndrome and Patau syndrome, which are characterized by low mental health and defects in the heart, kidneys, and scalp; Turner syndrome, which only affects women, is generally shorter, has a harder time reaching puberty, and is usually unable to conceive.

If an adult's chromosomes are translocated, he will not be affected, but when he has a child, half of his chromosomes will combine with half of his partner's chromosomes to become a complete set of chromosomes for the child, and the child may have "abnormal" chromosomes. This is the most effective way to prevent and treat the mouth.

As far as is known, the only thing a woman can do to avoid giving birth to a child with a chromosomal abnormality is to avoid being an advanced maternal age. As women become more pregnant, the likelihood of having a child with Down syndrome increases, especially in women over the age of 37.

In addition to regular check-ups during pregnancy, unmarried men and women or couples who are planning to have children should also go to the hospital for genetic disease counseling. If the woman has had more than one miscarriage and a family member or relative of both spouses has a chromosomal problem, the doctor will recommend that the couple take blood for testing, which can help to raise the possibility of the child suffering from congenital chromosomal disorders in the future.

Chromosomal structural abnormalities include deletions, additions, translocations, etc., which are medically called chromosomal deletions, insertions, duplications, inversions, translocations, etc.

There are many causes of chromosomal abnormalities, such as the age of the couple, the pregnant woman, the father, or the baby's exposure to radiation, all of which can alter the genetic pattern of the fetus.

Radiation X-ray exposure also affects genetic material, which affects gene function and arrangement.