AnthropogenicchromosomeThe number is 46 (23 pairs), 23 from the father and 23 from the mother.Sperm and egg carry 23 chromosomes respectively, which are combined into 23 pairs during fertilization, of which 22 pairs are autosomes, which determine human traits and characteristics, and the other pair is sex chromosomes, which determine human gender, male: XY, female: XX.
Chromosomal disease
There are 46 chromosomes in normal people. Under the action of some internal or local factors, abnormal chromosome numbers can occur - chromosome numbers increase or decrease;Chromosome structural abnormality - changes in translocation, deletion, handstand or combinatorial arrangement in rearrangement.Such diseases mainly include:21 trisomy syndrome(Congenital foolishness) Common nameDonner's syndrome。
Monogenic disease
Chromosomal disease
Mainly caused by gene mutationDNA moleculeThe sequence of internal bases is changed, or the combination is changed, so that the genetic information is wrong, and the enzyme or protein with normal function cannot be synthesized, causing disease.According to different genetic modes, single gene genetic diseases can be divided into: ① autosomal dominant genetic diseases ② autosomal recessive genetic diseases ③ X-linked recessive genetic diseases ④X-linked dominant inheritance 。This kind of disease mainly includes:hemophilia、Color blindness、AlbinismEtc.
Polygenic hereditary disease
Cleft lip - polygenetic disorder
It refers to the disease caused by the abnormality of two or more pairs of genes.The formation of this kind of disease is ① affected by genetic factors ② affected by environmental factors.Such diseases mainly include: cleft lip, cleft palateCongenital heart disease, schizophreniaessential hypertension、Adolescent diabetesEtc.
hemophilia
hemophilia
Hemophilia is a hereditary disease that can cause spontaneous bleeding. Generally, the incidence of hemophilia in boys is about 1/10000.Hemophilia is caused by the lack of the eighth factor of coagulation in the body.Girls with hemophilia genes generally do not have symptoms, but their sons may have hemophilia.Symptoms of hemophilia include prolonged bleeding after trauma or minor surgery, pain and swelling of muscles and joints due to internal bleeding.The degree and frequency of haemophilia bleeding varies from person to person.Some people only have sporadic small bleeding.When the situation is serious, the patient may suffer from muscle and joint injuries due to repeated internal bleeding.If the child has abnormal bleeding symptoms, parents should take him to the doctor immediately.The doctor will perform a blood test for the child to assess the ability of blood coagulation to determine the diagnosis.Women with a family history of hemophilia should be tested to find out whether they have the hemophilia gene, and seekGenetic counselingServices to assess the possibility of giving birth to a baby with hemophilia.During treatment, doctors can inject the eighth factor provided by parents to treat the bleeding symptoms.If the child often has bleeding, then parents may have to provide factor 8 regularly.The eighth factor used will not appear virus.Children with hemophilia should avoid engaging in dangerous activities, such as impact sports. As long as they bleed, they should be given factor 8 immediately, or they should be given factor 8 regularly. Muscles and joints should not be injured, and their life expectancy will be the same as that of ordinary people.
trisomy 21 syndrome
This is the most commonChromosomal abnormalityAbout one in 700 babies suffers from this disease.Children with trisomy 21 syndrome have obvious physiological characteristics, and their psychological development is also relatively slow.About 1/3 of the children were born to women over 37 years old.Women who once gave birth to children with trisomy 21 syndrome are also more likely to give birth to such children again.
symptom:
trisomy 21 syndrome
1. Upwardly inclined eyes, with obvious skin wrinkles on the inner corner of the eyelid.
2. A small round face with plump cheeks.
3. A big tongue that often sticks out.
4. Flat back extending to the head.
5. Slack and droop limbs.
6. Physiological development is slow.
7. Learning disabilities generally require special education.
8. Short stature.
Therefore, pregnant women of all ages should have blood tests no matter whether they belong to the high-risk group or not.A pregnant woman who has ever given birth to a child with trisomy 21 syndrome or who is over 37 years old should receive chorionic villus sampling, orAmniocentesis。The doctor will analyze these samplesEmbryonic cellTo check ifChromosomal abnormalityThe situation.If the test results show that the fetus has trisomy 21 syndrome, then parents should consider whether to terminate the pregnancy.When parents suspect that the child has trisomy 21 syndrome, they should take the child to the hospital for examination. The doctor will check whether the child has the characteristics of the disease, and carry out blood chromosome analysis for the child to confirm the diagnosis.In addition, doctors will also carry out heart surgery for childrenUltrasonic inspectionTo check whether there is filling deficiency. If the doctor suspects that the child's intestinal tract is defective, he will have an abdominal X-ray examination.If there are two defects mentioned above, surgery may be necessary.For a woman who has given birth to a child with trisomy 21, doctors will also provide genetic counseling services to assess the probability of trisomy 21 when she gives birth.Many children with trisomy 21 can survive to their prime, but 20% of them die before the age of 5, which is usually caused by severe heart disease.Adults with this disease are more likely to suffer from Alzheimer's disease andCoronary arteriosclerosis。
Sickle cell anemia
The red blood cells of patients with this disease have an abnormal heme called S heme, so they will be distorted.If a child inherits an abnormal gene from both parents, he will develop sickle cell anemia.But if a child inherits an abnormal gene from only one parent, he will carrySickle cell anemiaThat is, although there are no symptoms, the abnormal genes will be passed on to the next generation.Symptoms of the disease include: low spirit and shortness of breath, jaundice, severe pain in bones, chest or abdomen, which is caused by narrow blood vessel obstruction.Dehydration, cold or severe infection are more likely to cause the above symptoms.Sickle cell anemia is more common in childrenDiplococcal pneumonia。Sometimes there is insufficient blood supply to the kidney, spleen or brain, which causes damage to these organs.If a child has any of the above symptoms, he or she should take the child to the hospital for examination. Blood tests can confirm the diagnosis (many children are detected during blood tests at birth).The treatment includes folic acid to reduce the severity of anemia, penicillin to prevent infectionImmunizationIn order to prevent pneumonia infection, and if necessary, can also take painkillers.In order to prevent the onset of pain, you should make sure that your child drinks a lot of water, and avoid getting cold when he is young.If the child has a pain attack and is accompanied by the following symptoms, such as fever, sudden whitening of skin color, repeated vomiting or severe diarrhea, dyspnea or shortness of breath, abnormal sleepiness or listlessness, the child should be taken to the hospital immediately.People belonging to this high-risk group had better undergo blood tests to find out whether they have abnormal genes.If the fetus has sickle cell anemia, termination of pregnancy should be considered.With good medical care, most children with sickle cell anemia can grow up.If the child's condition is very serious and a suitable bone marrow donor can be found, then implementation can be consideredbone marrow transplantation。Once the bone marrow transplantation is successful, the disease can be completely cured.
Thalassemia
ThalassemiaIt is a kind of hereditary anemia, and people living along the Mediterranean coast, Africans and Asians most often suffer from it.Thalassemia is caused by defective genes that control heme production.Severe patients cannot produce normal heme, and their red blood cells are small and fragile, which will break soon. Mild patients will have slightly less red blood cells than normal red blood cells.Its symptoms include pale skin, long-term fatigue and shortness of breath.Thalassemia is mainly diagnosed by blood tests.Children with severe thalassemia can be treated with blood transfusion every month from a few months. However, frequent blood transfusion may eventually damage the heart, liver and other internal organs of children, because these organs may have excessive iron.This problem can be prevented by regular infusion of a drug called desferrioxaminc.Some children with severe thalassemia are generally in good condition if they receive regular blood transfusion and injection of drugs such as desferrioxamine.They can grow and develop normally, and most people can live to middle age.Mild thalassemia does not require any treatment.If the parents of a child with thalassemia want to have another child, they can calculate the probability of thalassemia in that child through genetic counseling.
anemia
Fragile X chromosome
This heritability xChromosomal abnormalityIt is a common cause of children's learning disabilities, and may also cause slight physiological abnormalities.The incidence rate of boys is about 1/000, and that of girls is about 1/2500.Women without symptoms may also carry defective chromosomes and pass them on to their children.
symptom:
1. Higher than average height.
2. The head is relatively large.
3. Mental development is delayed, and the girl's condition is slight.Boys can be moderate to severe.
4. Speech development is delayed, and boys usually have serious symptoms.
5. Characterized by autism.
6. Square, prominent jaw, long face, big ears.After puberty, the testicles of boys will appear particularly large.These characteristics are usually found in children after puberty.
If the parents suspect that the child has this disease, they should take the child to the hospital for inspection. The doctor may take his blood sample for chromosome analysis. If the test results confirm that his chromosome is indeed defective, the doctor will provide relevant genetic materials to assess the probability of abnormal reproduction.This disease is recognized by the medical community, and there is no specific treatment, so further research is needed.
Phenylketonuria
PhenylketonuriaIt is a genetic disease caused by the accumulation of amphetamine acid in the blood due to errors in chemical changes in the body.If not treated, phenylketonuria may cause brain damage to children.The incidence of this disease is about 1/10000.Generally, blood examination for phenylketonuria should be carried out routinely shortly after the birth of the baby.Symptoms of the disease include severe learning disabilities, a tendency to spasm, a special odor, and a rash like atopic eczema.At ordinary times, children have to eat vegetarian food, and may also have to takeNutritional supplements。Many cases still need medication.
Phenylketonuria
Once gave birthPhenylketonuriaThe mother of the baby will also have a high probability of giving birth to a child with this disease again, so pregnant women should carry out prenatal examination. Once the fetus is found to have phenylketonuria, termination of pregnancy should be considered.After treatment, most of the treated children with phenylketonuria have normal intelligence.A small number of children may have behavioral problems and learning disabilities. We usually recommend that patients take special diet for life.
cystic fibrosis
cystic fibrosis It is a serious genetic disease, which will cause repeated lung infection and intestinal absorption of nutrients.About one in 2000 children will suffer from cystic fibrosis.Cystic fibrosis is caused by gene defect.It causes mucus secretion, which cannot flow freely out of the respiratory tube, thus causing repeated infection.In addition, it may also cause insufficient pancreatic enzyme secretion, thus causing diarrhea.The symptoms of this disease include: 1. The child cannot grow normally and his weight does not reach the normal standard.2、Repeated cough。3. Long term diarrhea is usually accompanied by light colored, oily and foul smelling feces.If the child has any of the above symptoms, parents should take the child to the hospital immediately.The doctor will send the child's sweat to the laboratory for analysis. The sweat salt content of cystic fibrosis patients is higher than that of normal people.In addition, the child may also have to undergo genetic tests. Once the test results confirm that he has cystic fibrosis, the doctor will prescribe pancreatic enzyme for the child to take when eating to promote normal digestion of food.Doctors will also recommend a high calorie, high protein diet, and will also let children take vitamin supplements.Doctors may also prescribe antibiotics and recommend regular physical therapy to treat chest infections and help prevent long-term lung disease.After the guidance of the physiotherapist, parents should carry out general chest physiotherapy for the child as soon as possible. Once the child has any symptoms of pain, it is very important to take him to the hospital immediately.And in order to let the child absorb enough nutrition for normal development, parents should encourage him to eat more high calorie snacks.There is no effective treatment for cystic fibrosis, but if parents can find it early and adopt new treatment, the condition of children will also be greatly improved after treatment. Most children can grow up, and only a few children with serious conditions may have to accept heart and lung transplantation, which will improve their quality of life and increase their life.Parents who have given birth to children with cystic fibrosis or who have abnormal genes should receive gene counseling.Pregnant women should have prenatal examination. If the fetus has cystic fibrosis, it may be necessary to consider terminating the pregnancy.
Dietetic correction
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Ensure that nutrients are comprehensive and sufficient
The first shall meetHigh quality proteinThe supply of food such as milk, eggs, liver, fish and lean meat.If conditions do not permit, some of them can be replaced with bean products.
Second fruits such as hawthorn, fresh jujube, orange, kumquat, lemon, persimmon and peach, and various fresh vegetables such as carrots, green peppersTomatoesEggplant and various green leafy vegetables are rich sources of vitamins and inorganic salts, so we should try our best to adjust the varieties and eat them fully.
The third staple food should be coarse and fine grain.In addition, iodine rich foods such as kelp, jellyfish, seaweed, laver, sea rice, shrimp skin, and fish should be eaten alternately 1-2 times a week.
An ideal diet for pregnant women should include 250g milk, 2 eggs, 150g lean meat and animal viscera, 100-150g bean products, 500g vegetables, 250g fruits, 400-450g grains, 15g sugar and 20-25g vegetable oil for cooking every day.
Pay attention to adjusting the diet during the critical period
In the last three months of pregnancy, fetal brain cells andfat cellsThe "sensitive period" of proliferation. If you can eat more milk, egg yolks, liver, fish, vegetables and bean products in this period, so that the supply of protein, phospholipids and vitamins is sufficient, it will be effectively conducive to the increase of brain cells and the intellectual development of the fetus.In addition, pregnant women eat more walnuts, sunflower seeds, sesame seeds, peanuts, etcUnsaturated fatty acidRich food can reduce the incidence of children's skin diseases.If you can eat some ironVitamin B12Food rich in folic acid, such as liver, egg yolk, agaric, green vegetables and lobster sauce, can reduce the incidence of anaemia after birth.Eating iodine rich food regularly can reduceInfantile cretinismIncidence of.
Parents with poor intelligence or someNutritional deficiencyIn order to give birth to their offspring, more attention should be paid to nutrition supplement and diet regulation during pregnancy.
Use food to correct genetic defects
The appearance and body shape of children mainly depend on their parents' heredity, but it is possible to correct some genetic deficiencies by eating food during pregnancy.For example, parents are short, and they choose calcium andvitamin DRich food can promote the development of children's trunk and limbs, which may increase their stature;Often eat some liver, sesame and various colored vegetables to makevitamin AAdequate supply to promote eye development and hair growth;Pregnant women's meals often contain milk, fruit, walnuts, etc., which may make children's skin delicate, white and tender.
Therefore, good nutrition during pregnancy is the foundation of children's lifelong health, which must be paid attention to.
Related information
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Three month examination before pregnancy can effectively detect genetic defects（ObstetricsandGynecology）It published a study that introduced a method that can detect more than 90%Down syndrome(Downsyndrome).This combined blood test andUltrasonic inspectionThe early screening test can replace the commonly used "triple test", and can be carried out in the first six to eight weeks of pregnancy, which can detect more Down syndrome.Down syndrome is one of the most common genetic defects, with about one in every 600 newborns suffering from this disease.
The study, entitled "Screening Down syndrome with blood biochemistry and nuchal translucency in the first three months of pregnancy", was carried out by several units in collaboration.They include NTD Lab in Huntington, New York, CentroDiDiagnosiPrenatale in Palermo, ItalyNorth CarolinaChapelHill's Center for Gene Therapy and Medical Genetics and Washington'sGeorge Washington UniversityMedical Center.
In this study, researchersUltrasonic inspectionThe amount of fluid accumulated behind the neck of the fetus was measured, which is also called nuchal translucency.In addition, the researchers also measured the freeβ-The amount of hCG and PAPP-A.The results of the two tests were input into a mathematical formula, by which researchers could determine the risk of Down syndrome in the fetus conceived by the patient.Through this screening method, it can be found that about 5% of the fetuses are at risk of Down syndrome.Next, the researchers performed diagnostic tests on these high-risk patients, such as chorionic villus test (CVS) or amniotic fluid diagnosis.These methods can ultimately determine whether the patient's fetus has Down syndrome.The study showed that 91% of the high-risk group had Down syndrome fetuses.
This is from New YorkHuntington NTD LabThe new screening tests sold under the name Ultrascreen (R) have several advantages.It improves the detection rate of Down syndrome, ensures the safety of pregnant women with normal fetuses earlier, gives high-risk patients more time and more choices, and also determines whether the fetus conceived by the patient who decides to abort has Down syndrome.
Early diagnosis can be achieved by avoiding fluorescent chromosome test for children with genetic defects
Genes with congenital genetic diseases make many people worry about giving birth to unhealthy next generation, which is used by the medical communityFluorescence chromosome fishing techniqueIn the early pregnancy of pregnant women, we can take samples of fetal villus cells for special chromosome testing to know the baby's gene code, confirm whether there is a gene defect problem, and avoid giving birth to a gene defect baby in the future.
Some couples with congenital genetic diseases are worried about giving birth to babies with genetic defects!Yaxian's mother is still very sad and regretful when she recalls her 1-year-old 4-month old daughter who has died.Yaxian's mother said that she was a person with chromosome 22 deficiency. Although she was clinically quite normal, her daughter inherited her missing chromosome. She was born with heart disease, thymus deficiency, congenital immune deficiency, repeated infection with septicemia. Her condition was good and bad, and she had two heart operations. Finally, she was defeated by the disease and passed away.
Yaxian's death made her mother quite afraid of having another baby. Fortunately, through the prenatal genetic diagnosis technology of fluorescence chromosome fishing, she analyzed the chorionic villus cells of the fetus during the 9th to 18th weeks of pregnancy, and knew in advance whether the fetal gene chromosome was defective, so that Yaxian's mother finally gave birth to a healthy baby boy successfully.
Taipei Tzu Chi HospitalCai Liping, a pediatrician, said that this detection method is like fishing. The detection probe can catch normal genes. If the genes are defective, the probe will not respond, which is very helpful for gene screening of genetic diseases.Cai Liping said: if we want to make prenatal diagnosis, we can do it from two time points, one is about 10 weeks. We can do chorionic villus sampling to analyze fetal cells;Another time point is to do amniotic fluid at 16-18 weeks, which can also be used to culture fetal cells, and can also be seen by using such a fishing technique called chromosome fluorescence.
Cai Liping pointed out that fluorescent chromosome analysis technology can enable mothers with congenital diseases to carry out molecular genetic examination, including rare diseases such as leopard disease, ectodermal dysplasia, anhidrosis, post Marfan syndrome and retinal detachment, which can be tracked and monitored during pregnancy and occur early to avoid giving birth to babies with congenital defects.
