How to check down syndrome?

Question 1: What should I do if I find Down syndrome? Down syndrome, namely 2 1- trisomy syndrome, also known as congenital stupidity or Down syndrome, is a disease caused by chromosome abnormality (an extra chromosome 2 1). 60% of the children miscarried in the early fetus, and the survivors had obvious mental retardation, special face, growth and development obstacles and multiple deformities.

There is no effective treatment at present. The best way is to terminate the pregnancy before the pregnant mother gives birth. The contents of prenatal prevention for pregnant women are as follows:

1. Genetic counseling

The older the pregnant woman, the higher the risk rate. The recurrence risk rate of standard Down syndrome is 65438 0%. Parents of children with translocation should carry out karyotype analysis in order to find balanced translocation carriers: if the mother is D/G translocation, the risk rate of each fetus is10%; If the father is D/G translocation, the risk rate is 4%. Most cases of G/G translocation are sporadic, and their parents' karyotypes are normal, but 2 1/2 1 translocation carriers are also found, and their next generation 100% suffers from this disease.

2. Prenatal diagnosis

This is an effective measure to prevent the birth of children with Down syndrome. Couples who have a history of bearing this disease should make prenatal diagnosis, that is, chromosome karyotype analysis. Sampling includes amniocentesis of amniotic fluid cells in the second trimester, chorionic villi cells in the second trimester and umbilical cord blood lymphocytes in the second trimester. The determination of serum markers HCG and AFP in prenatal screening has certain clinical significance, because it can reduce the blindness of prenatal diagnosis of amniocentesis, prompt the existence of high-risk pregnant women, enable these pregnant women to do further prenatal examination and consultation, and prevent the birth of children with Down syndrome to the greatest extent.

Question 2: When to check the condition analysis of Down syndrome;

Down's screening is a detection method to calculate the risk factors of giving birth to Down's baby by extracting the serum of pregnant women, detecting the concentrations of fetal protein A and chorionic gonadotropin in maternal serum, and combining the expected date of delivery, age, weight and gestational age of pregnant women.

The best screening time for Down syndrome is 15- 20 weeks pregnant. If high risk is indicated, further amniocentesis and fetal chromosome examination are needed to determine whether Down syndrome exists.

Guiding opinions:

It is suggested that three-dimensional color Doppler ultrasound should be performed at 2 1-27 weeks of pregnancy, which is helpful to rule out fetal large organ malformation.

Question 3: What do you think of the screening of Down syndrome? Hello, your grades are very good, there is no risk, don't worry.

The point is that your test results are compared with the reference range.

For example, these three key points:

Down syndrome risk rate test results:117857 reference range (question 4: how to find out that the signs of down syndrome children after birth are very diverse, and many organs and tissues are abnormal. However, developmental malformations are usually not serious enough to be life-threatening. The following is a brief description of the clinical manifestations of children with Down syndrome from the aspects of facial and physical characteristics, circulatory system, digestive system, endocrine system, nervous system, reproductive system, behavior and life expectancy.

1. Facial and physical characteristics

The average weight and length of children at birth are generally low, and their muscle tension is low. The most prominent is craniofacial malformation. The skull is small and round, the pillow is flat, the face is round, the nose is flat, the palpebral fissure is thin and inclined outward, the eye distance is too wide, the epicanthus is obvious, the eyelashes are short and sparse, and strabismus often occurs. There are white spots on the iris, often accompanied by lens opacity. The mouth is small and the lips are thick, the tongue is large and often stretched, the ears are small, and the ears are low. Hair is straight and not curly. The back of the neck is short and wide, and the skin is redundant. Due to chondrodysplasia, the patient's limbs are short. Hands are wide and fat, palms are penetrating, fingers are short, and the fifth finger is often bent inward, short or lacking middle finger. Abdominal distension caused by low muscle tension often leads to rectus abdominis separation or umbilical hernia.

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2. Congenital heart disease

Echocardiography showed that patients with 1/2 or more had congenital heart disease. Mainly ventricular septal defect, atrioventricular conduction, atrial septal defect, patent ductus arteriosus. The most serious congenital heart disease is pulmonary vascular obstruction, which can lead to congestive heart failure. This potentially fatal complication develops much faster in children with Down syndrome than in children with the same heart disease but normal chromosomes.

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3. Blood diseases

Although the specific pathogenesis of blood diseases in children with Down syndrome is still unknown, it has been found that almost every blood cell in patients with Down syndrome is at risk of this abnormality. For example, polycythemia can be seen in newborns or cyanotic heart disease (blue children); Platelets may increase or decrease; Although the abnormality of blood system rarely leads to serious diseases, the probability of leukemia in children with Down syndrome is1150, while the incidence rate of ordinary children is only 1/2800.

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4. Gastrointestinal malformation

The incidence of digestive tract malformation is about 5%, which is mainly characterized by feeding difficulties, vomiting and aspiration pneumonia in the newborn. These malformations include duodenal stenosis or occlusion (3%), duodenal occlusion (0.9%), Hirschsprung's disease (0.5%), esophagotracheal fistula or esophageal occlusion (0.4%) and pyloric stenosis (0.3%).

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5. Endocrine system diseases

About1141Down syndrome newborns have congenital hypothyroidism, which is about 28 times that of normal people. In addition, about 30%~50% of older children show subclinical congenital hypothyroidism. A study found that about 7% of these children eventually developed hypothyroidism. About 250 children with Down syndrome have diabetes, twice as many as the normal population.

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6. Neurodevelopmental and behavioral dysfunction

Mental retardation is the most prominent and serious manifestation of this syndrome. Children's mental development is slow. They can sit up after 1 year old and start walking around 3 years old. The development of these symbolic movements, boys are a little later than girls. On average, boys can walk for 26 months and girls can walk for 22 months.

Within two years after birth, children with Down syndrome seem to have no cognitive impairment due to social care. However, after 2 years old, there was obvious language retardation; Children with Down syndrome don't begin to speak simple words until they are 2 years old.

Children's personality is soft and dull, rarely aggressive, and they don't know how to count, but sometimes they have a certain memory and are good at imitating others. Although children with Down syndrome are happy and amiable, their expressions are stiff. However, temperament research shows that, like other children, they also have their own development contours. In addition, 26 1 overseas follow-up studies on children with down syndrome found that the incidence of behavioral and psychological abnormalities was as follows: attention deficit hyperactivity disorder (6%), conduct disorder or hostile behavior (5%), aggressive behavior (7%), phobia (2%), abnormal diet (1%) and difficulty in solving.

A child's IQ is usually between 25 and 50. Children with better intelligence can learn ... >>

Question 5: What will happen to children with Down syndrome in the future? Down syndrome, also known as 2 1 trisomy syndrome, means that a fertilized egg has a pair of hemichromosomes 2 1. It is very likely that when the egg was formed, it did not divide normally during the first division, and all chromosomes 2 1 swam into an egg, which led to abnormal division of the egg and finally combined with * * to form a fertilized egg.

In fact, it may be because of the working environment of the mother and the age of the pregnant mother. The reason is complicated. If the mother is older, the child is more likely to get sick.

Remind the landlord that there is no cure for this disease, and the sick child may suffer from congenital heart disease at the same time and may die young. I hope to be mentally prepared.

There is also some information. I hope the landlord will pay attention to the following and express deep sympathy for the unfortunate experience. I hope this is just a drop in the bucket!

Down syndrome is caused by Langton? Dr. Tang named it. In a famous article, he pointed out and explained that atavism is one of the causes of various mental disabilities, including "Mongolian disease". This article was written in the report of 1866 London Hospital, but the symptoms he described are called "Mongolian dementia", and the literature reports on this symptom can be traced back to1early 9th century. It is called "Mongolian dementia" because people think that people with this symptom look like Mongolians in northern China.

Perhaps because of the sensation caused by Dr. Tang's report, people are becoming more and more interested in genetic diseases, which account for one third of the total population with severe mental disabilities. /kloc-After 0/9th century, people gave Dr. Langton Tang the honor of "discovering" this new and distinctive clinic, and called this symptom "Dr. Tang syndrome".

1959, people discovered the real cause of Down syndrome (now its name), or at least how it happened. When Jerome Lejeune and his assistant were working at the Paris Institute of Genetics, they reported their discovery that there was an extra chromosome on chromosome 2 1 in the gene combination of Down syndrome. There are 46 chromosomes in normal karyotype, of which 22 pairs are autosomes and 1 pair are sex chromosomes. The extra chromosome on chromosome 2 1 makes down syndrome patients have 47 chromosomes. Later scientific research found that this was because the 2 1 chromosome was not separated when it should be.

The extra chromosomes make children with this symptom obviously different from others in physiology and intelligence. These main differences will be listed below, but it must be remembered that not every child with Down syndrome has all these characteristics. How many characteristics people find has nothing to do with intelligence and acquired development. A good environment has a greater influence on people than innate genetic talent.

head

Short head, short front and back diameter. The back of the head is flat, which can be said to be flush with the back neck, and the neck is shorter and thicker. The weight of the brain is below average, but this should not be considered as a serious matter, because everyone has brain cells that can't be used up for a lifetime, and patients with Down syndrome are no exception. If not, it is a serious problem, because brain cells, unlike other cells in the human body, will not regenerate once they are over 20 years old.

Sometimes there are serious neck problems. Fortunately, it's only 1. 5% patients with Down syndrome have this symptom, which is called atlantoaxial subluxation, and it is mainly caused by the loose connection between the first spinous process and the second spinous process of the spine. Some sports dislocate bones and even lead to death, such as riding a horse, swimming and rolling forward. All children with Down syndrome should undergo neck X-ray examination at about three years old to rule out this possibility. If you have this problem, remind your child's family and caregivers to avoid doing the above exercise.

After all, it is natural to discuss intelligence. People with Down syndrome have very different intelligence. A few people have multiple disabilities, their IQ is almost impossible to measure, and they need lifelong care. Others are smarter, and their IQ reaches the level of normal people. Most people's IQ is between these two extremes and need the help of special education. Either go to a special school or a normal school with special educational facilities.

Most patients with Down syndrome will have early symptoms of Alzheimer's disease (a senile disease), but it is reported that their symptoms are milder than those of most patients with Alzheimer's disease. It seems that the brains of patients with Down syndrome have some resistance to Alzheimer's disease. This possibility has caused many ... >>

Question 6: What tests do you usually do for Down syndrome? Down syndrome, or three body 2 1- syndrome, also known as congenital stupidity or Down syndrome, is a disease caused by chromosome abnormality (an extra chromosome 2 1). 60% of the children miscarried in the early fetus, and the survivors had obvious mental retardation, special face, growth and development obstacles and multiple deformities.

1. Karyotype analysis of peripheral blood cells

Cytogenetic studies have found that when chromosome 2 1 long arm is trisomy, the individual has completely similar clinical manifestations to Down syndrome. On the contrary, individuals who are not trisomy in this area do not have such typical symptoms. It can be inferred that 2 1q22 region may be the key gene region of Down syndrome, also known as Down syndrome region. According to karyotype analysis, children with Down syndrome can be divided into three types:

(1) standard type accounts for 95% of all cases. The child has 47 somatic chromosomes and an extra chromosome 2 1 with a karyotype of 47, XX (or XY), +2 1.

(2) The translocation type accounts for 2.5% ~ 5%, and the total number of children's chromosomes is 46, mostly robertsonian translocation, which refers to a mutual translocation of proximal centromere chromosomes, mostly D/G translocation. In group D, chromosome 14 is dominant, that is, the karyotype is 46, XX (or XY),-14, +T, and a few are 15. About half of the children with this translocation type are hereditary, that is, their parents have balanced translocation chromosome carriers. The other is G/G translocation, which is rare, because two chromosomes 2 1 in Group G have centromere fusion to form an isoparametric chromosome t(2 1q2 1q), or 1 2 1 translocation to1.

(3) Chimeric body type accounts for 2% ~ 4% of the disease. Children have more than two cell lines (the two most common), one is normal and the other is 2 1- trisomy cell. The severity of clinical manifestations is related to the percentage of normal cells, which can range from nearly normal to typical phenotype. The higher the proportion of 2 1- trisomy cell line, the lower the intelligence.

2. Chromosome examination of amniotic fluid cells

Chromosome examination of amniotic fluid cells is an effective method for prenatal diagnosis of Down's syndrome, and pregnant women with "high risk" screening results need to confirm whether the fetus is a child with Down's syndrome. At present, the most commonly used technology for prenatal diagnosis is amniocentesis, that is, under the guidance of B-ultrasound, the needle is inserted into amniotic fluid through the abdomen of pregnant women, and amniotic fluid is extracted for chromosome analysis of fetal cells. Suitable for 16 ~ 20 weeks pregnant women. In addition to amniocentesis, prenatal diagnostic techniques include villus biopsy, fetal umbilical vein puncture and fetal endoscopy. The common karyotype is the same as that of peripheral blood cells.

3. Fluorescence in situ hybridization

Using the corresponding sequence of chromosome 2 1 as a probe, three fluorescent signals of chromosome 2 1 can appear in the cells of patients with down syndrome by hybridization with lymphocytes or amniotic fluid cells in peripheral blood. If the specific sequence of the core region of Down syndrome fish is selected as a probe, the abnormal position of chromosome 2 1 can be accurately located, and the accuracy of detecting the number and structural abnormality of chromosome 2 1 can be improved.

4. Prenatal screening of serum markers

It has been explored for many years to screen Down's syndrome by measuring serum chorionic gonadotropin (HCG), alpha-fetoprotein (AFP) and free estriol (FE3) in pregnant women. Free estriol is an indicator of the second trimester of pregnancy (after 13 weeks).

According to these three serological indexes (HCG and AFP can also be measured) and the age and weight of pregnant women, the risk rate of children with Down syndrome can be calculated, and further diagnosis can be made according to the risk rate.

5. routine x-ray, ultrasound, electrocardiogram, EEG and other examinations.

Some children can find changes such as congenital heart disease, delayed bone age and abnormal EEG.

Question 7: How to diagnose Down syndrome? Down syndrome is a type of congenital stupidity, and Zhou Zhou, who can command, has this disease. Children should be taken to the hospital to have their feet examined. Probably not Dunn's son. Don't scare yourself. The son with Down syndrome has many symptoms. The following article has a detailed explanation:

down syndrome

1. Cause:

DownSyndrome, also known as Mongolian disease, was first commented by Dr. J.L.Down, a British doctor. The patient's appearance resembles that of an oriental in the eyes of westerners, hence its name.

Down syndrome is caused by congenital chromosomal abnormalities. Most patients have errors in chromosome 2 1 during genetic division, resulting in redundant chromosomes in the nucleus; A small part is caused by translocation.

2. Symptoms:

Children with Down syndrome have many obvious symptoms in appearance and even constitution. Their intelligence is lower than that of normal children, and their IQ is usually only 40 to 60, but they are gentle. Children with this disease have slow development and low muscle tone, which makes them learn to sit and walk later than normal children. They also have a very special appearance and are easy to identify. Children with this disease generally have long eyes, oblique eyes, flat nose, small mouth, small teeth and big ears. Most patients have ape-shaped palm prints (commonly known as broken palms), special hoofprint on fingers, and the distance between the first and second toes is extremely wide.

3. Treatment:

At present, no drugs have been invented to improve the intelligence of mentally retarded people; Therefore, the treatment of Down syndrome is mainly based on education. However, this disease is often accompanied by respiratory tract infection, gastrointestinal obstruction and other diseases. Congenital heart disease and thyroid dysfunction can be cured or controlled.

4. Prevention:

The average incidence of Down syndrome is 1/600, and the incidence of infants born to elderly women is more than five times higher. Male patients are mostly infertile, but the probability of female patients passing it on to the next generation can be as high as 1/2. In addition, 5% patients belong to translocation type, which is highly heritable and has nothing to do with the mother's age or any family history. Therefore, it is necessary to diagnose the patient's chromosome and check the translocation.

In the early pregnancy, facial examination of fetal villi or amniotic fluid cells, assisted by ultrasonic scanner to look at the head, hands and feet of the fetus, can determine whether the fetus has Down syndrome, so that parents can decide whether abortion is needed.

The following is an introduction to the testing method of Down syndrome.

1, pregnant women ≥35 years old, and the incidence of chromosome number aberration is not high (Down syndrome is 2 1- trisomy aberration) 2. Open neural tube defect and abdominal wall defect should be paid attention to when maternal alpha-fetoprotein is high. Pay attention to the possibility of 2 1- trisomy when the value is low, especially when the free estriol is also low. 3. Three results of maternal screening: maternal alpha-fetoprotein, human chorionic gonadotropin and free estriol increase or decrease, and three indicators can be detected in combination with maternal age. The false positive rate of 60% Down syndrome is about 6.6%. Human chorion only accounts for a single index of gonadal hormone (HCG), and the detection rate of Down syndrome is high. 4. Amniotic fluid can be taken to determine the alpha-fetoprotein of fetal exfoliated nuclei and analyze the karyotype; Such as alpha-fetoprotein exceeding the standard, swelling, hydrocephalus, anencephaly and so on. Such as spina bifida, meningocele, hydrocephalus and anencephaly. If the karyotype analysis shows 2 1- trisomy, the fetus can be diagnosed as Down syndrome.

Down syndrome, or 2 1 trisomy, also known as congenital stupidity in China, is one of the most common serious birth defects. The clinical manifestations are: the patient's face is special, his eyes are upturned, his nose is flat, his tongue often sticks out, he has muscle weakness and runs through his hand. The vast majority of patients are severely mentally retarded, accompanied by various organ abnormalities, such as congenital heart disease, leukemia, digestive tract malformation and so on. The disease occurs almost all over the world, and there are few ethnic differences. According to statistics, the incidence of chromosomal abnormalities in newborns is 5-6/ 1000, and down syndrome is about 1/750. Most patients occur randomly, but with the increase of mother's age, the incidence rate also increases. The average mother is over 35 years old, and the birth rate of this child can be as high as 1/350.

The inspection results cannot be determined because the test methods and reference values may be different from place to place.

The results of B-ultrasound showed that fetal dizziness was the development of skull under B-ultrasound, which could be seen in 12 weeks. & gt