[Case] Appearance: The baby looks like grandma.
Netizen "I'm Ma Bao": My son is going to kindergarten, and his grandmother usually takes care of him. Recently, I often hear people say that your baby is more and more like his grandmother. I take a closer look, it really is. This is very strange. My husband is similar in appearance and height to his father (my father-in-law) and his mother. Why did he come to my son, who looks like my grandmother instead of my husband? Is it because grandma brought too much?
[My opinion]:
This is the fault of atavism! The so-called atavism refers to a family in it runs in the family. The first generation and the third generation have similar phenotypes, but the second generation has no such phenotypes. It is the result of genetic, epigenetic and quantitative inheritance.
In the case of this family, the husband carries the genes of his parents (grandparents), but the genes of his father are epigenetic and have an advantage in appearance. Therefore, a husband is like a father, but his mother's genes are passed on to him, but they are not shown. By the third generation, that is, grandson's generation, this hidden gene has become epigenetic, which is why grandson looks more like grandma.
Of course, in addition to genetic factors, this netizen is worried that grandma will bring too much, so the child is like grandma. In fact, there is some truth, but it is not reflected in the appearance characteristics. Because non-genetic factors are also very important for the influence of the day after tomorrow. For example, children's tone of voice, way of speaking, angry or happy expression, and some habitual actions of doing things will all be influenced by the people they get along with the most. These factors are also one of the reasons why children look like grandmothers.
If adults have some bad habits, for the sake of children, it is suggested that this netizen can communicate with her mother-in-law to prevent children from learning. I believe that grandma and mom are the same in loving their children.
What is atavism?
From the genetic point of view, the transmission of pathogenic genes is passed down from generation to generation. Once an individual does not inherit a specific disease-causing gene from his parents, his descendants generally do not have to worry about genetic diseases caused by this disease-causing gene. However, there are also some genetic diseases in atavism, which are called sex-linked inheritance in genetics.
The vast majority of children with hereditary diseases are male. When tracing the family disease, we can find that the patient's mother is normal and healthy, but his grandfather is a patient with the disease. Two characteristics can be summarized:
(1) Sex-linked genetic diseases are passed from grandfather to grandson, skipping the mother's generation, with obvious atavism;
② All the patients were male, so the disease was transmitted from male to female.
Interesting phenomena of genes and heredity
Do children's genes come entirely from their parents?
1, whose height is hereditary?
Parents are 50/50. Under the premise of nutritional status, 70% of a child's height is in the hands of parents, and the heredity of parents is the main factor to determine the child's height, because 35% of the factors to determine the child's height come from his father and 35% from his mother. If the parents are not tall, it depends on the baby's 30% efforts the day after tomorrow.
2. Who is genetic intelligence?
Mother's intelligence is inherited to a certain extent, and it is also influenced by acquired factors such as environment, nutrition and education. According to scientists' assessment, the influence of heredity on intelligence accounts for about 50%-60%. As far as heredity is concerned, mothers are smart, and most of the children born are smart. If they were boys, they would be smarter. This is because human intelligence-related genes are mainly concentrated on the X chromosome. Women have two X chromosomes, while men only have 1, so the mother's intelligence plays a more important role in heredity.
3. Who is the hereditary personality?
Dad. Character is inherited from father. Although the formation of personality has innate factors, it is mainly influenced by the day after tomorrow. Comparatively speaking, dad's influence will be greater than mom's. Among them, the role of fatherly love has a greater influence on daughters. A psychologist thinks: "Father plays an important role in the formation of his daughter's sense of self-esteem, identity and gentleness." Another expert suggested that a father can teach his daughter many important lessons and experiences in life, so as to make her character more colorful.
4. Who inherited the appearance?
Skin color: always follow the natural law of "average after multiplication", leaving people no choice. If parents have dark skin, there will never be children with white skin; If one person is white and the other is black, most of them will give their children a "neutral" skin color, and some will be more inclined to one side.
Eyes: (Eye type) Children's eye type and size are inherited from their parents, and big eyes are dominant over small eyes. If one of the parents has big eyes, the child with big eyes may be bigger. (Double eyelids) Double eyelids are dominant inheritance, and life babies with single eyelids and double eyelids are most likely double eyelids. But both parents have single eyelids, and the average child also has single eyelids.
(eye color) Dark colors such as black are dominant inheritance compared with light colors. In other words, people with black eyes and blue eyes don't have blue eyes.
Long eyelashes are also dominant. As long as one parent has long eyelashes, children are likely to inherit long eyelashes.
Nose: Generally speaking, the nose is big and high, and the nostril width is dominant. If one of the parents has a straight nose, it is likely to be passed on to the child. The inheritance of the nose will continue into adulthood. The nose is short when you are a child and high when you are an adult.
Ears: The shape of ears is inherited, and big ears are dominant over small ears. As long as one parent has big ears, then the child is likely to have a pair of big ears.
Jaw: It is a dominant inheritance and cannot be "discussed". Either parent has a prominent chin, and children often have similar chins without exception, which is somewhat bizarre.
Obesity: Children will have a 53% chance of becoming obese. If one of the parents of Wuhan IVF is obese, the probability of obesity will drop to 40%. This shows that about half of being fat can be determined by human factors. Therefore, parents can make their posture symmetrical through reasonable diet and adequate exercise.
Baldness: the creator seems to favor women and let baldness be passed on only to men. For example, if the father is bald, the probability of passing it on to his son is 50%, and even the mother's father will leave his 25% probability of baldness to his grandchildren. This sexual genetic tendency of passing on men but not women makes men very helpless.
Acne: This facial disease that worries both boys and girls is actually related to heredity. Because if both parents have suffered from acne, the prevalence rate of children will be 20 times higher than that of children without family history.
Leg shape: those fat legs that look like parents can be shaped into slender and strong legs through adequate exercise. But if the leg is too long or too short because of heredity, it can't be remolded, so we have to let it be.
How to avoid the occurrence of genetic diseases?
The first level: carefully choose the "other half"
Men and women who have confirmed their love relationship should have a comprehensive and systematic health examination before going through the marriage registration formalities. In particular, avoid consanguineous marriage. It is also necessary to investigate whether both families have serious genetic diseases.
The second level: genetic counseling before pregnancy
Genetic counseling, also known as genetic consultation, aims to limit the birth of children with genetic diseases through counseling, thus reducing the frequency of genetic diseases and improving the quality of the population. Its task is to predict future generations, determine the risk rate of siblings and children of patients suffering from the same disease again, and provide suggestions and guidance for patients or their families.
The third level: prenatal screening to avoid the birth of children.
Prenatal screening is mainly aimed at some diseases that have no good treatment at present, and its purpose is to prevent the birth of defective children. Generally, it is performed at the time of pregnancy 16 -20 weeks, and 2-3 ml of peripheral blood of pregnant women is taken for examination. If high-risk possibility is found (high-risk factors exceed 1/270), further amniotic fluid culture is needed. If there is a problem with the fetus, induce labor in time to avoid the birth of the child.
Pregnancy examination: an essential disease examination item
1, medical history
In addition to your existing diseases, you should also let the doctor know about any genetic problems in your family (such as Down syndrome or cystic fibrosis). At the same time, you should also tell the doctor the contraceptive method you are using, whether you have ovulation or menstrual problems, and whether you have a history of abortion.
2, cervical cancer smear examination
When was the last time you had a cervical smear? If you want to have a baby next year, you need to do it again. Doctors usually don't give you a smear during pregnancy or within 6 months after the baby is born.
3. Urine test
If you are at risk of urinary tract infection, the doctor may ask you to have a urine test. Urinary tract infection is related to abortion, low birth weight and premature delivery.
4. Blood test
A blood test is to check whether you have anemia or other abnormal conditions. According to your family history, the doctor may also check whether you have sickle cell anemia and thalassemia. Thalassemia is more common in southern areas such as Guangdong, Guangxi and Fujian than in the north.
5. Blood pressure check
Pregnant women with chronic hypertension are more prone to preeclampsia and placental problems, so it is very important to control blood pressure before pregnancy.
Step 6 check
You may need to be screened for diseases such as hepatitis B and syphilis. Pre-pregnancy screening and treatment (if it is AIDS, it is necessary to control the disease), which is helpful to get through pregnancy smoothly. The doctor may also let you do screening for chlamydia, bacterial vaginitis and candida vaginitis.
Many infections that may lead to miscarriage or birth defects are actually preventable. A quick blood test can tell you whether you have been vaccinated against diseases such as rubella. Although there is no evidence that rubella vaccination during pregnancy is related to birth defects, it is prudent to wait until 1 month after vaccination if rubella live vaccine is needed. This will give your body time to get rid of the virus in the vaccine.
7. Parasitic disease examination
Parasitic diseases such as toxoplasmosis are harmless to adults, but may be dangerous to newborns and fetuses. Toxoplasma gondii is mostly transmitted through cat feces or undercooked meat.
As long as you pass the blood test, you can determine whether you have had or have immunity. If not, you should be more careful, avoid eating undercooked meat, and pay more attention when handling raw or undercooked meat. Wear gloves when gardening at home and let others take out the cat's feces. But if you have a cat, you are probably immune, but you should also check whether you have immune antibodies before you get pregnant.
8. Take folic acid
Taking folic acid supplements and making sure that your diet includes foods rich in folic acid can prevent neural tube defects such as spina bifida. The Dietary Guidelines for China Residents issued by the Nutrition Society of China in 2007 pointed out that women of childbearing age should supplement 400 micrograms of folic acid every day from the third month before pregnancy and continue throughout pregnancy. However, if you have a family history of neural tube defects or other chronic health problems (such as epilepsy), you may need to increase the amount and take 5 mg folic acid supplements every day.
9. Quit smoking, drinking and giving up drugs
A lot of evidence shows that smoking, taking drugs and drinking alcohol are not good for you and your future baby. The ideal thing is to quit these hobbies before getting pregnant. The doctor may provide you with a smoking cessation plan to help you quit smoking before pregnancy. If you are addicted to alcohol or drugs, the doctor may also advise you to seek other auxiliary treatments to help you give birth to a healthy baby.