Pediatric Patau Syndrome
Introduction
Introduction to Pediatric Parie Syndrome Parsal syndrome, trisomy13syndrome, was recognized as trisomy 13 on chromosome 13 in 1966. It is also a relatively common chromosomal aberration disease. Its clinical features are mainly growth and development disorders and multiple Sexual deformity. The 13-trisomy syndrome has a higher mortality rate. basic knowledge The proportion of illness: 0.0002% Susceptible people: infants and young children Mode of infection: non-infectious Complications: congenital heart disease
Cause
Pediatric syndrome
Causes:
The disease is a chromosomal aberration disease, and the cause is still unclear.
Pathogenesis:
It is generally found that the 13-trisomy syndrome has a peak age distribution of 25 and 38 years old. It seems that the latter peak is closely related to the age of the pregnant mother. It is known that the abnormal chromosome number may be due to the destruction of the balance of normal genes. There are different degrees of congenital anomalous manifestations. The trisomy may be associated with the dose effect and/or positional effect of the gene. Since the germ cells of one of the parents are not separated during meiosis, they cannot be evenly distributed to two. In a sub-cell, a gamete with two chromosomes appears. When this gamet is combined with a normal gamete, an abnormal number of chromosomes is generated. The band-forming technique proves that the extra chromosome is the chromosome 13 of group D, that is, chromosome 13. Trisomy syndrome.
Prevention
Pediatric syndrome prevention
The etiology of 13-trisomy syndrome remains unclear, and the relevant preventive measures against genetic diseases:
1. Prohibit close relatives from getting married.
2. Premarital examination to discover genetic diseases or other diseases that should not be married.
3. The detection of the carrier is determined by group census, family survey and pedigree analysis, laboratory examination and other means to determine whether it is a genetic disease, and determine the genetic mode.
4. Genetic counseling
(1) Genetic counseling:
1 Patients diagnosed with hereditary diseases and their relatives.
2 consecutive families with unexplained diseases.
3 congenital primary intelligence is low, suspected of genetic related.
4 balance translocation chromosomes or carriers of disease-causing genes.
5 Women with unexplained recurrent miscarriage.
6 sexual dysplasia.
7 have a family history of hereditary diseases and intend to marry and give birth.
(2) The main objectives of genetic counseling:
1 pair of patients themselves:
A. Determine the diagnosis of the disease, the cause of the disease, the genetic pattern, the treatment and the prognosis, and further analyze whether the patient's disease-causing gene or chromosomal abnormality is caused by a new mutation or a previous generation.
B. Relieve the physical and mental pain and anxiety of the patient.
C. Give early attention to patients who are not ill, and give necessary treatment.
2 For both parents and relatives:
A. Detection of carriers and recessive cases in the family.
B. Determine the risk of developing a member of the family.
C. Help couples who are at risk of having children with genetic diseases to help them scientifically and consider birth plans in accordance with family planning regulations.
(3) Genetic estimation of pediatric diseases:
1 The difference between children's diseases is the intrauterine environmental factors, birth injury and hypoxic ischemic disease or genetic factors, so it is necessary to understand the history of the parents (such as taking drugs, the nature of work, etc.), The mother's pregnancy history, the birth history of the child, etc., in addition to various physical and chemical, biological factors on the embryo and the fetus.
2 Asking about family history and analyzing genealogy is one of the basic methods of genetic counseling.
3 According to the clinical manifestations, combined with the relevant laboratory tests, make a clear diagnosis, such as chromosomal abnormalities must be combined with karyotype analysis can be determined.
(4) Identify the genetic characteristics of each genetic disease: it is of great significance for guiding birth.
5. Prenatal diagnosis of prenatal diagnosis or intrauterine diagnosis is an important measure of preventive eugenics.
The prenatal diagnostic techniques used are:
1 amniocytes culture and related biochemical examination (amniotic puncturing time is 16 to 20 weeks of pregnancy is appropriate);
2 pregnant women blood and amniotic fluid alpha fetoprotein determination;
3 ultrasound imaging (applicable in about 4 months of pregnancy);
4X line examination (after 5 months of pregnancy) is beneficial for the diagnosis of fetal skeletal deformities;
5 Determination of sex chromatin in villus cells (40 to 70 days of conception), predicting fetal gender to help diagnose X-linked genetic diseases;
6 application gene linkage analysis;
7 fetal mirror examination.
Through the application of the above technology, the birth of a fetus with severe genetic diseases and congenital malformations is prevented.
Complication
Pediatric syndrome Complications congenital heart disease
Growth and development disorders, feeding difficulties, often occur asphyxia, apnea and motor seizures, accompanied by multiple malformations, mostly associated with congenital heart disease, digestive tract, urinary system, reproductive system deformity.
Symptom
Pediatric parietal syndrome symptoms common symptoms convulsions ventricular septal defect clitoris hypertrophy iris defect hydronephrosis deafness
Multiple malformations are more serious than Edwards syndrome and Down's trisomy syndrome, growth and development disorders, feeding difficulties, often suffocation, poor living ability, intelligent retardation, low muscle tone, often apnea and sports seizures, accompanied by There is a change in the peak rhythm of EEG.
The head of the child is small, the forehead is retracted, the anterior ankle is large and the suture is wide, the cranial scalp is ulcerated, and the cleft palate is horizontal. It can be seen from different degrees of small eyes to no eyes, wide eye distance, cataract, iris defect and retinal development. Abnormal, visible one-eyed deformity, small mandible, 2/3 cases see cleft lip, often accompanied by cleft palate, low ear position, flat wheel with unclear boundary, and deafness, face, forehead or nape may have one or more blood vessels Tumor, neck skin relaxation, 12th rib dysplasia or absent, 80% of cases have congenital heart disease, mainly ventricular septal defect, patent ductus arteriosus, atrial septal defect, etc., gastrointestinal malformation can be seen poor colonic rotation, pancreas Or spleen tissue ectopic, etc., common six-finger (toe) malformation, nails protruding excessively, 30% to 60% of children with urinary malformations, polycystic kidney, hydronephrosis, kidney and double ureter, 80% of men have Cryptorchidism, see scrotal deformity, women can have double-horned uterus, clitoris hypertrophy and double vagina.
Examine
Pediatric parietal syndrome examination
1. The karyotype analysis of peripheral blood lymphocytes mainly shows three types of karyotypes:
(1) 13-trisomy (standard type): produced by chromosome 13 without separation, accounting for about 80%.
(2) Translocation type: about 15%, mainly from the D group chromosomal translocation, the translocation between chromosome 13 and chromosome 13-15, such as t (13q; 14q).
(3) Chimeric type: about 5%, the 13-trisomy is chimeric with normal chromosomes, and the karyotype is 47XX (or XY) + 13/46XX (or XY).
2. Amniocentesis Chromosome Examination Amniocentesis Chromosome examination is an effective method for prenatal diagnosis of 13-trisomy syndrome, but termination of pregnancy must be in the second trimester, and karyotype analysis is similar to peripheral blood lymphocyte chromosome examination.
3. Fluorescence in situ hybridization can detect the number and structural abnormalities of chromosome 13 through the specific probe of the core region of 13-trisomy syndrome. FISH hybridization is performed using the probes that have been mapped, and the number of chromosome 13 is detected by the Q banding method. And structural anomalies, greatly improving accuracy.
4. Fetal hemoglobin detection often has fetal hemoglobin persisting for too long. The blood cell morphology examination shows that the neutral multinucleated cells have pedicles or pedicled protrusions, which are sickle-like.
X-ray films, ultrasound, electrocardiogram, EEG, etc. can be routinely performed. Children with congenital heart disease can be found; abnormal EEG changes, peak rhythm changes; X-ray examination of six-finger (toe) malformation; Imaging examination revealed various malformations of the digestive tract and urinary tract.
Diagnosis
Diagnosis and diagnosis of Pediatric syndrome in children
The diagnosis of trisomy 13 is mainly based on cytogenetic examination and clinical features.
Different from other chromosomal aberrations, such as 21-trisomy, 8-trisomy, and 9-trisomy syndrome, cell chromosome examination can help identify.
