I. Counseling.
1. Genetic counseling is a series of conversations and discussions between the counseling physician and the subject (the patient with a genetic disease or his family) about the occurrence of a genetic disease in the family, the risk of recurrence, and the problems faced in diagnosis and prevention, so that the patient or his family can have a comprehensive understanding of the genetic disease and choose the most appropriate decision. Wang Xiaojuan, Department of Obstetrics and Gynecology, The Second Hospital of Qiqihar Medical College
2. It can be divided into pre-marital counseling, pre-birth counseling, risk of recurrence counseling, etc.
Second, pre-consultation clinic :
1. understanding the general situation of prenatal counselors and the content of the counseling analysis of all sources of outpatient medical records of those receiving counseling.
2. Composition: pre-pregnancy consultation accounted for 10%, early pregnancy consultation accounted for 10%, mid-term consultation accounted for 30%, late pregnancy consultation 30%, infertility 5%, history of miscarriage 5%, other medical records accounted for 10%. Urban 91.2%, rural 86.5%.
3. Consultation content: drugs, adverse pregnancy history, preconception/conception, infertility, miscarriage history, age, psychological, physical factors, abnormalities, etc.
4. The necessity of preconception counseling and prenatal counseling, and the need for counseling clinicians to master the relevant knowledge and continuously improve the level of counseling.
III. Knowledge :
Genes and chromosomes, genetic testing, laws of inheritance, mode of inheritance, genetic risk
Genealogical analysis, consanguineous marriage, genetic counseling, genetic diagnosis, genetic screening, prevention and control principles
IV. Indications for genetic eugenics counseling
1. senior pregnant women: all 35 years old and above, with or without a husband aged 40 and above
2. pregnant women with a family history of genetic diseases
3. pregnant women with mental retardation or those with mental retardation in their family;
4. Pregnant women with congenital malformations;
5. those who have had multiple spontaneous abortions
6. those with a history of stillbirth or deformed delivery
7. patients with infertility.
8. those who need to have their parentage identified
9. Those who have been exposed to substances that may be malformed during pregnancy, especially during early pregnancy, including drugs, physical and chemical substances that have been recognized as malformation-causing and suspected to be malformation-causing.
Those who have married close relatives within three generations.
V. Internal genetic diseases
1. Blood genetic diseases
Sea anemia G6PD deficiency (sericea) hemophilia
Neural a muscle genetic disease
Pseudohypertrophic muscular dystrophy, ankylosing muscular dystrophy, fragile X syndrome
Huntington’s disease
Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, progressive spinal
Myasthenia gravis
Schizophrenia
Cardiovascular genetic diseases
Congenital heart disease, primary hypertension, familial hypercholesterolemia
2. Coronary heart disease and atherosclerosis
Genetic diseases of endocrine system
Diabetes mellitus
Genetic diseases of the digestive system
Hepatomegaly (Wilson’s disease)
Genetic diseases of the respiratory system
Allergic asthma
Genetic disorders of the urinary system
Recognition of polycystic kidney failure
VI. Surgical genetic disorders.
Skeletal genetic disorders, dwarf syndrome
Connective tissue genetic disorders, Marfan syndrome, osteogenesis imperfecta
Oncogenetic disorders, breast/ovarian cancer, cervical cancer, colorectal cancer, Wilms cancer, retinoblastoma
Ocular genetic diseases, retinitis pigmentosa, congenital cataract, molecular genetics of major blindness and teratogenic diseases in ophthalmology
Ear, nose and throat genetic diseases, congenital deafness
VII. Obstetrics and gynecology genetic diseases.
Chromosomal diseases, Down’s syndrome common sense trisomy 18, Turner’s syndrome
Reproductive-developmental genetic disorders, sexual inversion syndrome, Y chromosome microdeletion syndrome
Early and mid-pregnancy screening
Prenatal diagnosis
VIII. Pediatric genetic disorders.
Congenital metabolic disease, phenylketonuria, galactosemia, glycogen storage, mucopolysaccharide storage, neurosphingolipid storage.
Others: intrauterine infections and congenital malformations, paternity testing.
IX. Other genetic diseases.
Albinism, vitiligo, mitochondrial genetic disorders, drug genetic disorders
X. Typical consultation Q & A.
I had a blood test at 14 weeks of pregnancy and the results indicated that my fetus might have Down Syndrome with a 1:71 chance (risk). They are basing it on the HCG and methemoglobin concentrations in the blood. Mine is high, is the blood test result reliable? Do I have to terminate the pregnancy?
Eleven. Answer.
Genes on chromosomes can be altered by so many factors, such as: heredity, radiation, poisoning, etc. The fact that there has never been a Down’s syndrome patient in the family does not guarantee that there are no invisible carriers of this gene. The test results are indicative of the possibility of the existence of this disease, although not 100% accurate, and we will inform you of the possibility of the existence of this risk and let you make your own choice.
XII. Down syndrome, also known as congenital stupidity and trisomy 21, is the most common chromosomal disorder and cause of mental retardation, with an incidence of about 1 in 700 newborns. Depending on the karyotype, Down syndrome is divided into three types: simple trisomy 21, chimeric and translocation. Down syndrome originates from chromosomal non-segregation during meiosis occurring in the egg or sperm, which usually occurs randomly, with about 95% of the non-segregation originating from the mother and only about 5% occurring during spermatogenesis. The result is an extra chromosome 21, and the extra chromosome disrupts the balance between the genetic material of the normal genome due to the dosage effect, mostly complicating congenital heart disease, and the incidence of leukemia in patients is 10-20 times higher than in the general population. Life is difficult to take care of oneself, and the prognosis of patients is generally poor, with about 50% dying before the age of 5.
There is a lack of effective treatment for Down syndrome.
XIII. Maternal age is closely related to the occurrence of Down’s syndrome. Maternal age and risk of fetal Down syndrome development are
Age: 20.25.30.35.38.40.42.45 years.
Risk: 1/1400 1/1100 1/1000 1/380 1/175 1/110 1/65 1/30
About 90% of Down syndrome can be detected by early and mid pregnancy tests, PAPP-A, free beta-hCG and AFP in maternal blood, combined with ultrasound.
For high-risk fetuses, chromosomal karyotype analysis by techniques such as chorionic villus biopsy or amniocentesis live umbilical cord blood puncture can confirm the diagnosis, followed by abortion management.
XIV. Down’s syndrome is a genetic disorder. Theoretically, if one of the couple has trisomy 21, 1/2 of the children born will have the disease. Most cases of simple trisomy 21 Down syndrome arise due to a random occurrence in gamete formation, with normal parents, no family history, and a strong association with advanced age. Therefore, it is possible to carry a fetus with Down syndrome even if neither of the couple is a Down syndrome patient.
In cases where one parent has a balanced chromosomal translocation, 1/3 of the children born are normal, 1/3 are translocated, and 1/3 are carriers of the balanced translocation. If one parent is a 21/21 balanced translocation carrier, 100% of the living infants will be 21/21 translocation patients.
XV. ①How to reduce the risk of having a fetus with Down’s syndrome?
Although prenatal diagnosis is only advocated routinely for pregnant women of advanced age (35 years or older), this does not mean that pregnant women under 35 years of age are not at risk for the development of a Down syndrome fetus. Screening and genetic counseling in early and mid-pregnancy can help identify fetuses at high risk for Down syndrome, and those diagnosed through prenatal diagnosis such as amniocentesis should be aborted as early as possible. , ②
Is it necessary to induce abortion for a fetus diagnosed with Down syndrome?
The diagnosis of Down’s syndrome is a serious fatal and disabling disease, and there is a lack of effective treatment for Down’s syndrome, so abortion is generally recommended for fetuses diagnosed with Down’s syndrome.
Is there a greater risk of having a fetus with Down’s syndrome after a previous pregnancy?
Pregnant women who have already had a fetus with Down syndrome have a 1-2% increased chance of having another pregnancy with Down syndrome, as well as an increased chance of other chromosomal disorders, so it is important to be prepared for prenatal diagnosis.
④Why does the risk of Down’s syndrome increase with the age of the pregnant woman?
The reason is not clear. By artificially increasing the susceptibility to chromosomal non-segregation with maternal age, the risk increases.
XVI. Can people with Down syndrome marry and have children normally?
Male patients with trisomy 21 are infertile and 50% are cryptorchid, while female patients are occasionally fertile. Some patients with Down syndrome with reduced clinical symptoms, such as some balanced translocation carriers or chimeric patients, may be normal in appearance, but after marriage and pregnancy, spontaneous abortions or stillbirths often occur and may be considered for discouragement or embryo selection through preimplantation genetic diagnosis.
XVII. Prenatal counseling
Definition: assessment of the risk of birth defects in this pregnancy for various high-risk factors, explanation to parents, and prenatal diagnosis according to different indications; explanation of the results of prenatal diagnosis and the possible outcome of the pregnancy.
XVIII. Emergence of defects: mainly refers to structural or functional abnormalities that arise during the embryonic or fetal period and can occur in any organ system. (Important cause of miscarriage, stillbirth, stillbirth, neonatal death, and infant fetal fracture.)
XIX. Causes of the occurrence of congenital malformations
Wilson (1972) synthesized the information from five international birth trap seminars and found that
Genetic factors caused by birth defects accounted for 25%, environmental factors accounted for 10%, genetic factors and environmental factors interact with each other and unknown causes accounted for 65%. (The three common causes of birth defects: ① genetic factors ② environmental factors ③ genetic factors + environmental factors)
XX. National congenital malformation parity
1996 2002
Total cleft lip (14.5/million) Total cleft lip (13.6/million)
NTD (13.6/million) NTD (10.6/million)
Polydactyly (9.2/million) Polydactyly (12.6/million)
Congenital hydrocephalus (6.5/million) Congenital hydrocephalus (7.5/million)
Congenital heart disease (6.2/million) Congenital heart disease (10.2/million)
Limb shortening (5.2/million) Limb shortening (6.2/million)
XXI. Birth defect prevention
Type of measure.
Primary prevention Prevention of occurrence, reducing the rate of birth defects
Secondary prevention Avoiding births and reducing the rate of partial birth defects
Tertiary prevention Avoiding disability, reducing the rate of disability, and reducing the “burden of disease”
XXII. Birth defects intervention
Primary intervention: premarital screening and premarital counseling
Pre-conception screening and pre-conception counseling ;
Folic acid and multivitamin interventions.
Secondary intervention: prenatal screening, prenatal diagnosis, intrauterine fetal treatment, and termination of pregnancy.
Tertiary intervention: newborn screening, malformation correction.
XXIII. Heilongjiang Province, 9 localities 1993-2002 sick and disabled children approval disease parity table
No. Disease name Number of children with disabilities
1 Cerebral palsy 1383
2 Congenital heart disease 1211
3 Congenital neurological disorders 906
4 Cerebral underdevelopment 825
5 Mental retardation 735
6 Paralysis 480
7 Deafness 443
8 Hip dislocation 342
9 Cerebral hemorrhage sequelae of meningitis 255
10 Thoracic spinal deformity 183
Total 6843
Central nervous system diseases accounted for 78% of the top 10 diseases.
XXIV. Developmental malformations of the nervous system common to spina bifida.
Classification: ① spondylolisthesis; ② spondylospinal bulge; ③ spinal cord exstrophy.
It is often associated with lower limb paralysis, urinary and fecal incontinence and hydrocephalus. Most of the severe cases die within a week after the onset.
XXV. Total cleft lip
Higher incidence
Ultrasound technology, improved prenatal diagnosis
primary interventions and tertiary interventions
such as dose of folic acid, smoking intervention, genetic counseling, etc.
Diagnosis: diagnosable by prenatal ultrasound, difficult to diagnose cleft palate alone; diagnosable by naked eye after birth, can be combined with syndromes or chromosomal disorders
Treatment: surgical recovery, along with feeding, speech and hearing training and dental, craniofacial and orthopedic treatment.
XXVI. Cleft lip combined with cleft palate
A polygenic disorder with environmental factors including maternal diabetes, maternal anti-paralytic drugs or folic acid anti-knotting agents and the influence of alcohol lamps.
The lip is formed at about 45 days of embryonic life, and if the lip develops a closing defect, it often wants to extend the palate and lead to the development of cleft palate. Early pregnancy Thi is susceptible to infection.
XXVII. Congenital heart disease
Internal causes: genetic factors, chromosomal abnormalities and genetic malformations
External causes: viral infections such as rubella, mumps, influenza, etc. The first trimester of pregnancy is a critical period that affects the development of the heart and is also a risk period for congenital heart disease
The use of certain drugs and exposure to X-rays account for about 30% of cases
The rate of Down’s syndrome babies is higher in older women over 35 years old, and 25% of these babies have congenital heart disease.
High incidence of hypoxic ductus arteriosus in highland areas. Fetal echocardiography
Gestational age: 20-22 weeks, review if necessary, some patients can be missed.
XXVIII. Maternal serum screening
The trisomy 21 AFP and uE3 values are reduced, while hcG is significantly increased, i.e., the latter has the highest sensitivity.
Most use a risk ratio of 1:270 as the cutoff and recommend screening positive individuals for Tar karyotyping.
XXIX. Genetic screening
Detection of genes for genetic disease cure or susceptibility in the population. In recent years, with the development of individualized medicine, genetic screening also includes the detection of genetic polymorphisms to evaluate the correlation with certain diseases and responsiveness to certain drugs. At present, many countries and regions have established screening methods mainly for certain genetic diseases that have a high incidence, are serious or can be prevented at an early stage.
Depending on the purpose and target population, genetic screening can be divided into carrier screening, prenatal screening, neonatal screening, population screening, and drug-response screening. drug-response screening), the first three types are most commonly used.
In order to reduce the rate of birth defects in China, the National Family Planning Commission has launched the “Birth Defects Intervention Project” in 1999, mainly through genetic screening, to reduce the incidence of Down’s syndrome, congenital neural tube defects, congenital hypothyroidism, phenylketonuria, thalassemia, G6PD deficiency and other diseases in China or the rate of disability and death. To fully ensure the safety of mothers and infants and improve the quality of the Chinese population.
Thirty. Prenatal diagnosis: It refers to the application of various methods to detect the health status of the fetus before birth, make a diagnosis of the diseased fetus, and then reduce the birth rate of congenital defects through selective abortion or intrauterine treatment to achieve the purpose of eugenics.
It is based on genetic counseling, mainly through genetic testing and imaging, to make a clear diagnosis of high-risk fetuses and achieve fetal selection through selective abortion of the fetus, thus reducing the birth defect rate and improving the quality of eugenics and population.
XXXI. Prenatal diagnosis for those diseases
Diseases with clear diagnostic criteria and accurate and reliable prenatal diagnostic methods.
Diseases with severe symptoms that cause stillbirth, stillbirth or disability.
Diseases for which there is no effective treatment.
Diseases with high genetic risk.
Thirty-two. Indications for prenatal diagnosis
Pregnant women aged 35 years or older.
Pregnant women with positive serum screening in early or mid pregnancy.
Pregnant women in which one of the spouses is a patient with chromosomal disorders, or has had a pregnancy or child with chromosomal disorders
Pregnant women in which one of the spouses is a patient with a congenital neural tube defect, or has ever conceived or given birth to a child with this disease
Pregnant women with a history of unexplained spontaneous abortion, history of malformation, history of stillbirth or stillbirth
Pregnant women carrying a fetus at high risk of severe monogenic genetic disorders
by abnormal fetal ultrasound findings (including those with excessive amniotic fluid)
a history of exposure of one of the spouses to a remembered substance
fetuses suspected of intrauterine infection.
XXXIII. Methods of prenatal diagnosis for sampling
Traumatic methods mainly include amniocentesis, chorionic villus sampling, umbilical cord blood sampling, fetoscopy and embryo biopsy, etc. At present, prenatal diagnosis is still dominated by traumatic methods, with amniocentesis, umbilical cord blood sampling and chorionic villus sampling being the most commonly used.
Non-invasive methods include ultrasonography, maternal peripheral blood marker measurement and fetal cell testing.
Sampling carries the following risks.
transient fetal bradycardia.
Preterm delivery or intrauterine fetal death in 0.1-0.9%.
blood leakage from the umbilical cord placenta after cord blood sampling.
Very rare intra-amniotic cavity infection after amniotic fluid extraction.
Thirty-four: common consultation questions
1. What is an advanced pregnancy? Is a pregnant woman under the age of 35 pairs, while her husband is over 40 years old, also considered a senior pregnancy?
A pregnant woman is said to be of advanced maternal age when she is 35 years of age or older, regardless of whether it is her first pregnancy or multiple pregnancies, and regardless of whether she has ever given birth to a mature, normal child. When a pregnant woman is under 35 years of age and her husband is over 40 years of age, they are also considered to be of advanced age and the incidence of chromosomes in their fetus increases with age and should be diagnosed prenatally.
2. When to perform chorionic villus sampling, amniocentesis and umbilical cord puncture?
The verification century for chorionic villus sampling is 10-12 weeks of gestation; amniocentesis is 16-22 weeks, preferably 16-18 weeks; and umbilical cord puncture can be performed from 20 weeks until the second trimester. It is up to the physician to decide which method is appropriate according to the patient’s specific situation and the physician’s own level of practice.
3. What is the accuracy of prenatal diagnosis results?
Prenatal diagnosis is affected by various experimental conditions, and generally has a misdiagnosis rate of about 1%. Contamination of maternal cells during sampling can seriously affect the accuracy of the diagnosis. If there is doubt about the parentage of the fetus, the diagnosis is not in accordance with the genetic law.
4. What is the greater risk of miscarriage caused by three procedures: chorionic villus sampling, amniocentesis and umbilical cord puncture?
The safety of the procedure is greatly increased with the B-guided procedure, but there is still a certain risk of miscarriage. The risk of miscarriage with chorionic villus sampling is about 0.6%. Young’s membrane puncture is about 0.5%. The risk of cordocentesis is similar to that of Young’s membrane puncture.