Do you know the symptoms and causes of “chromosomal abnormalities”?

 

A chromosomal abnormality is a disease in which an abnormality in the number or structure of chromosomes changes in one or both of several autosomes or sex chromosomes. In addition, there are congenital abnormalities and acquired abnormalities. Congenital abnormalities are cases in which an abnormality occurs in the reproductive cells of the fertilized egg stage. This time, we explain the symptoms, causes, tests and diagnosis, and treatments for chromosomal abnormalities.

What is a chromosomal abnormality?

Chromosomes are inside the cell and several genes are recorded. Genes record the design information of specific proteins that function according to cell types, and are made of DNA = deoxyribonucleic acid.

Normal human cells = Dei Freud has 46 autosomes, 22 to 44 autosomes and 1 to 2 sex chromosomes. There are two types of sex chromosomes: X and Y chromosomes. Females have two X chromosomes = XX, and males have one X chromosome and one Y chromosome = XY. There are about 1000 genes in one chromosome, and there are about 50 genes in each band according to the chromosome infection method.

A chromosomal abnormality is a disease in which an excess or deletion occurs in the number of chromosomes and various symptoms appear due to abnormal gene expression due to quantitative imbalance of gene groups. In addition, even structural abnormalities that are not quantitative imbalances cause gene expression disorders due to chromosomal cuts, resulting in various disorder symptoms.

In cases where there is one or more extra chromosomes (one extra = trisomy, two extras = tetrasomi) and one missing = monosomy, trisomy occurs on all 23 pairs of chromosomes. A aneuploidy, known as an abnormality in chromosome number, is when the number of chromosomes other than 23 to 46 is increased or decreased by one to several chromosomes. Also, triploids and tetraploids can be seen in the fetus, and triploids are born with 69 chromosomes, but they do not live long.

Triploidy is most often caused by fertilization of two spermatozoa, and can also occur when a diploid egg or sperm is formed. In the case of triploid origin from the father, an abnormal placenta is formed, and in the triploid origin from the mother, an early spontaneous abortion. A tetraploid has 92 chromosomes, and when this division occurs in the sex chromosomes, there are no sex chromosomes called XXY or XYY.

In addition, structural abnormalities of chromosomes include abnormalities in a part of a chromosome or an abnormality in which part or all of a chromosome is incorrectly combined with another chromosome = translocation, missing a part of a chromosome = deletion syndrome, duplication, etc.

Deletion is the absence of part of one of the two chromosomes, resulting in an imbalance of the chromosomes. Both of the original chromosomes function the same size, but if part of one of the two is missing, it loses its function = so symptoms of failure appear. The severity of symptoms depends on the number of genes on the deleted chromosome and the size of the fragment.

Chromosomal abnormalities occur on all chromosomes, including sex chromosomes, and large abnormalities can be observed under a microscope in tests called chromosome analysis or karyotyping. In addition, for small chromosomal abnormalities, fluorescence in situ hybridization = FISH or dedicated genetic test = chromosome microarray analysis, etc., are used to scan chromosomes to find excess or defective parts.

Down's syndrome, turnerosis, and cancer are known diseases caused by chromosomal abnormalities, and the most common chromosomal abnormalities are 21 trisomi = Down syndrome, 13 trisomi, and 18 trisomi, which can be confirmed under a microscope during karyotype analysis.

Chromosomal excess or deletion increases the incidence and risk of having a child with the chromosomal abnormality as women become pregnant, but the risk of having a child with the chromosomal abnormality does not change as men age.

Depending on the type of chromosomal abnormality, abnormalities such as death from the embryonic or fetal stage before birth, intellectual disability, short stature, convulsive seizures, heart disease, and cleft palate may occur.

Chromosomal abnormalities are caused by chance, chemotherapy, radiation, etc., and the symptoms expressed by the abnormality are diversified, and too strong chromosomal abnormalities can make it difficult to give birth and cause miscarriage.

chromosomal abnormalities

Chromosomal abnormalities include Down's syndrome, Turner's syndrome, and Klinefelter's syndrome. Specific symptoms include heart failure symptoms such as dyspnea, dyspnea, and feeding disorders, and systemic symptoms such as constipation, vomiting, and convulsions.

In addition, chromosomal abnormalities may occur in cancer cells, and malignant tumors such as leukemia or lung cancer may develop. In addition, it can be a determining factor in your response to medications.

What are the causes of chromosomal abnormalities?

Human somatic cell = In Freud, there are a total of 46 sex chromosomes, including 22 to 44 autosomes assigned from 1 to 22, and 1 to 2 sex chromosomes such as X chromosome and Y chromosome. Contains genes necessary to function.

Chromosomal abnormality is an abnormality in the number of 46 chromosomes, and in Down's syndrome, there are 3 chromosomes 21, and as a result, various systemic symptoms appear. In addition, in cases of chromosomal structure abnormalities, there are cancer-specific genetic changes, which lead to the development of cancer.

How are chromosome abnormalities tested and diagnosed?

Chromosomal abnormality testing and diagnosis are performed using blood samples, blood, oral mucosa, and cancer cells. A representative method is the G-bandeinG=G band staining method, which diagnoses the number of chromosomes.

Testing for chromosomal abnormalities varies, such as as a prenatal test when the baby is in the womb, or when cancer develops.

Prenatal testing detects certain chromosomal abnormalities in the fetus by cells obtained by amniocentesis or cilia. If the fetus has an abnormality, more detailed tests are done, such as analyzing a pregnant woman's blood sample and screening tests to determine whether the fetus does not have a specific genetic disorder to identify the birth abnormality.

This test is performed because a small amount of fetal-derived DNA is contained in the blood of a pregnant woman. It is called non-invasive prenatal testing = NIPT. Non-invasive prenatal testing can characterize the risk of 21 trisomi = Down syndrome, 13 trisomi, 18 trisomi, and other chromosomal abnormalities, but cannot establish a diagnosis and requires further testing.

What is the treatment for chromosomal abnormalities?

Treatment of chromosomal abnormalities is difficult at the present time, and symptomatic treatment is implemented according to the symptoms that have occurred. For example, for heart disease caused by Down's syndrome, surgery or medical treatment is performed, and for mental development delay, nursing treatment is performed. In some cases, in vitro fertilization is performed when infertility occurs. If a malignant tumor occurs due to a chromosomal abnormality, treatment such as surgery, chemotherapy, or radiation is performed after evaluating the spread of the lesion.

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Chromosomal abnormalities can be passed on to the next generation as well as the person who develops them, and there are cases of genetic cow-shelling. Although basic treatment for chromosomal abnormalities is not yet available in modern medical care, folic acid intake to prevent neural tube obstruction, screening tests that investigate whether parents have a history of specific genetic abnormalities, or genetic abnormalities before transfer to the mother's womb for embryos obtained through in vitro fertilization It is important to consult with a medical institution because some congenital abnormalities such as tests can be prevented in some cases.