Hello everyone, today I will answer the following questions for you. Regarding polygenic genetic diseases, what are polygenic genetic diseases? Many people still don’t know. Now let’s take a look. Get up and take a look!
Contents of this article
- What is genetics pq
- What is recessive inheritance
- What are hereditary diseases
- What are polygenic genetic diseases
One , What is pq in genetics
1. p and q respectively represent the gene frequencies of two different genetic diseases in the population. p refers to the short arm of the chromosome, and q refers to the long arm of the chromosome.
2. The change in the position of a chromosome segment is called a translocation. It is accompanied by a change in gene position. When the translocation occurs within one chromosome, it is called a translocation or intrachromosomal translocation. When the translocation occurs between two homologous or non-homologous chromosomes, it is called an interchromosomal translocation.
3. The translocation of homologous chromosomes mainly occurs on chromosomes No. 10 and No. 14. The chromosome arms are the parts of the chromosomes in the nuclear cells. Structure name. During metaphase of cell division, each chromosome contains two chromatids, which are called sister chromatids.
4. The two monomers are connected to each other at the centromere, which is narrowed, so it is also called the main constriction scar. The part from the centromere to the ends of the chromosome is called the chromosome arm. If the centromere is not in the center of the chromosome, it can be divided into long arm (q) and short arm (p).
2. What is recessive inheritance
1. Recessive inheritance Heredity means that either parent carries a certain disease-causing gene but does not develop the disease. The gene may be passed on to future generations in a way that may cause disease in future generations.
2. For example, X chromosome recessive genetic diseases, if one parent carries this chromosome, the daughter will not have the disease; if both parents carry this disease The disease chromosome will cause the disease in the daughter.
3. What are hereditary diseases
Hereditary diseases are divided into four categories, namely chromosomal genetic diseases, single-gene genetic diseases, and polygenic genetic diseases. And mitochondrial genetic diseases. Among them, chromosomal genetic diseases are mainly diseases caused by chromosomal abnormalities, such as Down syndrome. Common diseases such as albinism and hemophilia are polygenic genetic diseases, such as anencephaly and spinal diseases. Clefts, coronary heart disease, asthma, cleft lip and palate and other diseases; mitochondrial genetic diseases, such as Alzheimer\’s disease and maternally inherited diabetes.
4. What are polygenic genetic diseases
1. Among mental diseases, schizophrenia (SZ) should be more familiar to people, and it is the most harmful.
2. Most people think it is caused by excessive life stress or other mental abnormalities. The unfortunate occurrence of this disease
3. But in fact, schizophrenia is closely related to human genetics. :2em;\”>4. There are three genes in the chromosome that are related to schizophrenia. The first is DTNBP1, which plays an important role in the release of glutamate in the brain and can improve the brain\’s ability to resist damage. The second It is NRG1, which has the effect of inducing nerve growth and renewal. The third one is DISC1, which also plays an important role in nerve function.
5. When these three. When genes mutate, the prevalence of schizophrenia will increase, and patients will show symptoms such as delusions, hallucinations, and loss of will, and may also be suicidal.
6. In addition, there is autism, which is also due to changes in various genes, leading to disorders in the formation of nerve synapses and leading to mental defects. Moreover, autism also has genetic heterogeneity, that is to say, different people have different susceptibility genes. There may be differences.
7. People with autism will show symptoms of social difficulties, language disorders, and stereotyped behaviors.
8. Another very common disease that may surprise you is also related to genetic factors, that is, its heritability reaches 62%. Regulation is very complex, and many genes are related to it
9., and congenital heart disease, such as aortic stenosis, etc.
10. The above diseases are all polygenic genetic diseases, which have many unique characteristics.
11. First of all, after the cross between two individuals, the resulting individuals are mostly intermediate types, and the variation in the population is very extensive.
12. Secondly, its incidence rate is relatively high and it is a common disease. It has a tendency to aggregate in families but there is no obvious inheritance pattern, and as the family level decreases, the risk of the disease decreases rapidly. The amazing thing is that it also has ethnic differences, which proves that the gene pools of different ethnic groups are different.
13. In genetics, there are several indicators to measure polygenic genetic diseases: The risk of disease caused by inheritance is called susceptibility. But genetic factors alone sometimes do not manifest into specific traits, and environmental factors are needed to induce them. The risk posed by this combination of genetics and environment is called susceptibility.
14. With susceptibility, an indicator is needed to measure the stage at which the body will become sick. This minimum is called the threshold.
15. When the mean value of susceptibility is closer to the threshold, the susceptibility level is higher and the incidence rate is lower.
16. But these are very abstract indicators. Specifically when it comes to estimating the risk of disease, we only need to look at these four factors:
17. The first one is the relative level. The closer the disease is, the greater the prevalence. , the farther away the disease is, the smaller the prevalence is.
18. The second is the number of patients in the family. The more patients, the higher the risk.
19. The third is the severity of the condition. The more severe the condition, the higher the risk for relatives.
20. The last one is special. The prevalence of some polygenic genetic diseases is related to gender. The threshold for some genders is relatively high, so the symptoms are not very obvious, but their children will still be at a higher risk of developing the disease. This effect is called the Carter effect. Congenital pyloric stenosis falls into this category.
21. In short, the characteristics of polygenic genetic diseases are quite different from those of single-gene genetic diseases. Polygenic genetic diseases involve many factors, so in geneticThe process also looks more \”golden\”.
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