Pediatric Digeorg syndrome
Introduction
Introduction to Digeol's syndrome in children Diggol syndrome (DGS) is associated with chromosome 22q11 deficiency and should be considered the sum of the most serious group of clinical diseases. The first letter of each word is abbreviated as "CATCH" 22 syndrome, meaning that it is due to the absence of 22q11. Cardiac, Abnormal, Thymic, Cleft, and Hypocalcemia. basic knowledge The proportion of illness: 0.0001%-0.0003% Susceptible people: children Mode of infection: non-infectious Complications: juvenile rheumatoid arthritis anemia thyroiditis
Cause
The cause of Digeorg syndrome in children
(1) Causes of the disease
The disease is caused by some factors (such as viral infection, poisoning) leading to the development of the third and fourth pharyngeal sac neural crest in early pregnancy, causing thymus (often accompanied by parathyroid gland) hypoplasia or non-development, often accompanied by cardiovascular, maxillofacial Department, ear and other developmental malformations, prone to occur in children born to older parents, some children suggest a defect associated with chromosome 22q11, mainly the loss of 22q11.2 (del22q11).
(two) pathogenesis
DGS is a group of multi-deformed complexes including pharyngeal arch, which has complex etiology. Possible factors include contact-induced malformation and maternal diabetes. Most patients with DGS (90%) and cardiac malformations have gene deletion, high-risk mutation or transduction in 22q11. The gene fragment is between D22S75 (N25) and GM00980, and its length is 200-300 kb. The frequently mutated region is between D22S427 and D22S36, and the other susceptible region is the distal end of FCF2. Candidate mutated genes, including NSCR/LAN/IDD, citrate transporter gene (CTP) and DGCR6, are not yet known.
DGS also has other chromosomal site abnormalities, including haploid 10q13, 18q21 and 17p13, 9q diploid and homologous chromosome 18q.
Prevention
Pediatric Diggolger Syndrome Prevention
Pregnant woman health care
It is known that the occurrence of some immunodeficiency diseases is closely related to embryonic dysplasia. If pregnant women are exposed to radiation, receive certain chemical treatments or develop viral infections (especially rubella virus infections), they can damage the fetal immune system. Especially in the early pregnancy, it can affect multiple systems including the immune system. Therefore, it is very important to strengthen the health care of pregnant women, especially in the early pregnancy. Pregnant women should avoid receiving radiation, use some chemical drugs with caution, and inject rubella vaccine to prevent as much as possible. Virus infection, but also to strengthen the nutrition of pregnant women, timely treatment of some chronic diseases.
2. Genetic counseling and family survey
Although most diseases cannot determine the genetic pattern, genetic counseling for diseases with defined genetic patterns is valuable if genetically immunodeficiency in adults will provide the developmental risk of their children; if a child has autosomals Recessive genetic or sexually linked immunodeficiency disease, it is necessary to tell parents that their next child is likely to be sick, for patients with antibodies or complement deficiency patients should check the antibody and complement levels to determine the family disease For some diseases that can be genetically mapped, such as chronic granulomatosis, parents, siblings and their children should be genetically tested. If a patient is found, it should also be performed among his or her family members. Check that the child's child should be carefully observed at the beginning of the birth for any disease.
3. Prenatal diagnosis
Some immunodeficiency diseases can be prenatally diagnosed, such as cultured amniotic fluid cell enzymology can diagnose adenosine deaminase deficiency, nucleoside phosphorylase deficiency and some combined immunodeficiency diseases; fetal blood cell immunological test can be Diagnosis of CGD, X-linked no-gammaglobulinemia, severe combined immunodeficiency disease, thereby terminating pregnancy and preventing the birth of the child.
Patients with Digeorg syndrome have a 50% chance of transmitting the disease to their offspring. A chromosome analysis of amniotic fluid cells or chorionic cells reveals that 22q11 deficiency can be used for prenatal diagnosis, parents with congenital heart disease or those with a confirmed 22q11 deficiency. It is the focus of prenatal examination, and prenatal ultrasound examination can find cardiac malformations. Based on the above, it is very important to make early and accurate diagnosis, to give specific treatment early and to provide genetic counseling (prenatal diagnosis or even intrauterine treatment).
Complication
Pediatric Diggolger syndrome complications Complications juvenile rheumatoid arthritis anemia thyroiditis
Can be complicated by hand and foot convulsions, repeated serious infections, weak and not easy to survive; may have neuropsychiatric development and cognitive impairment, progressive muscle rigidity, gait instability; autoimmune diseases, such as juvenile rheumatoid arthritis , autoimmune hemolytic anemia and thyroiditis.
Symptom
Symptoms of Digeol's Syndrome in Children Common Symptoms Repeated pneumonia Repeated infections Abnormal body gait instability Wheellet dysplasia Oral Candida infection Pulmonary atresia Small head convulsion Longitudinal short
1. Cardiac abnormalities Most patients have left heart outflow tract malformations, and other lesions have right heart outflow tract malformations including pulmonary atresia and Fallot quadruple sign, right ventricular outflow tract and pulmonary artery stenosis.
2. The hand and foot convulsions caused by hypocalcemia and hypocalcemia usually occur within 24 to 48 hours after birth. One patient was diagnosed with hypocalcemia for the first time at the age of 5, and 40 patients with low calcium for 40 years of long-term follow-up. The blood was corrected, 4 died, and the remaining 10 patients continued to receive treatment. The first two weeks after birth, hypocalcemia was particularly prominent, but most of them were temporary and resolved with age.
3. Facial features Facial features include long facial features, spherical tip and narrow nose, cleft palate, flattened humerus, widened eye distance, squinting, low lop ear with occlusion of the ear and dysplasia of the ear and hypomania. Other rare body abnormalities have microcephaly, short stature, slender fingertips, inguinal hernia and scoliosis.
4. Repeated infection of children with complete DiGeorge syndrome due to thymic dysplasia caused by immunodeficiency, often prone to repeated infections, manifested as chronic rhinitis, repeated pneumonia (including Pneumocystis carinii pneumonia), oral Candida infection and diarrhea, The child is very weak and not easy to survive.
5. Neuropsychiatric problems With the improvement of treatment methods, the number of survivors of DGS patients increased, neuropsychiatric problems have been paid attention to, children with mild neuropsychiatric development and cognitive impairment, most children with IQ of 73 ± 10, Progressive muscle rigidity, gait instability, etc. suggest a neurodegenerative change.
6. Autoimmune diseases DGS has a higher chance of developing autoimmune diseases than normal children, including juvenile rheumatoid arthritis, autoimmune hemolytic anemia and thyroiditis.
Examine
Pediatric Diggolger syndrome examination
1. Electrolyte and hormone detection
Serum low calcium and high phosphorus can be found, and parathyroid hormone is reduced or absent.
2. Immune function test
Of the 18 cardiac surgery cases, only 3 were able to see the thymus in the mediastinum.
(1) Incomplete DGS: There is residual thymus tissue, T lymphocyte proliferative response is normal, T11 cell function is significantly reduced, the number of lymphocytes at birth is 500-1500/mm3, and the normal range is reached at 1 year old, and the number of B cells is normal. Even more, there may be high IgGemia, high antibody response and autoantibodies. It is also reported that the affinity and persistence of the antibody response to the vaccine is not as good as that of normal children of the same age.
(2) Complete DGS: The presence or absence of residual thymus tissue is not a criterion for determining complete DGS, and the defect of T cell proliferative response can be considered as complete DGS. As the age increases, the increase in the number of T cells does not improve the proliferative response. The number of NK cells is also reduced, the number and function of damage are consistent with the degree of damage of T cells, the number of B cells is increased, immunoglobulin can be increased or decreased, IgA deficiency and anti-diphtheria-tetanus toxoid specificity The antibody is low.
3. Prenatal diagnosis and clear disease carriers
The chance of DGS patients passing the disease to the offspring is 50%. The chromosome analysis of amniotic fluid cells or chorionic cells found that 22q11 deficiency can make prenatal diagnosis. Parents with congenital heart disease or confirmed 22q11 deficiency are prenatal examinations. The main target, prenatal ultrasound examination can be found in cardiac malformations, although the first child is a child with DGS, and the second child is rarely seen, but prenatal examination should still be performed.
Film degree exam
Thoracic radiological examination may suggest no thymography, but this does not fully represent T cell dysfunction. X-ray findings of cardiac and macrovascular abnormalities, such as right arterial arch, pulmonary artery dilatation and cardiac enlargement, etc., resonance found in some cases of cerebellar vermis and The posterior cranial fossa becomes smaller and the small cyst is formed near the anterior horn. Echocardiography can confirm the type of cardiac malformation. Prenatal ultrasound examination can detect cardiac malformation. Brain CT, EEG and cardiovascular angiography should be performed.
Diagnosis
Diagnosis and diagnosis of Digeolger syndrome in children
According to the corresponding clinical manifestations of the disease, laboratory and X-ray examination, found that thymus deficiency, parathyroid gland and T cell dysfunction, etc., can diagnose the disease, in which hypoparathyroidism is low, T cell dysfunction is essential Conditions, other performance may or may not be diagnosed.
Different from other primary, secondary immunodeficiency diseases, according to clinical characteristics and laboratory-assisted examination can help identify.
