Helix hypoplasia

Introduction Insufficiency of the auricle is one of the symptoms of Digeol's syndrome in children. Facial features of children with Digolger syndrome include long face, spherical tip and narrow nose, cleft palate, flattened humerus, widened eye distance, squint, low lop ear with earring depression and auricular dysplasia and mandible too small.

Cause

(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, resulting in hypoplasia or dysplasia of the thymus (often accompanied by parathyroid glands). Often accompanied by cardiovascular, maxillofacial, ear and other developmental deformities. Some children are prone to occur in the children born to older parents, and some of them are related to chromosome 22q11 defects, mainly the deletion of 22q11.2 (del22q11).

(two) pathogenesis

DGS is a group of polymorphic complexes including the pharyngeal arch. The etiology is complicated, and the possible factors are contact with teratogenic preparations and maternal diabetes. Most DGS (90%) patients and patients with cardiac malformations have a gene deletion in 22q11. The high-risk mutant or translocated gene fragment is between D22S75 (N25) and GM00980, and its length is 200-300 kb. The frequently mutated region is between D22S427 and D22S36. Another easily mutated region is the distal end of FCF2. The exact pathogenic or candidate mutant genes to date have not been clarified. These candidate genes include N25 (related to skeletal muscle and inclusion factor heavy chain gene CLTCL), DGCR/LAN/IDD, citrate transporter gene (CTP), and DGCR6.

DGS also has other chromosomal site abnormalities, including haploid 10q13, 18q21 and 17p13, 9q diploid and homologous chromosome 18q.

an examination

Related inspection

Otolaryngology CT examination mammography

Immunological examination

This disease only affects T cells. The cellular immune function is very poor. The absolute count of peripheral blood lymphocytes is <1.5×109/L, mainly because the number of T cells is significantly reduced, and the E-ring cell formation rate is less than 10%. The number of peripheral blood B cells increased, and the serum immunoglobulin concentration was normal.

2. Other auxiliary inspections

X-ray examination of the patient without thymus.

3. Histopathological examination

Lymphocytes in the deep cortical thymus-dependent region of the lymph nodes. The thymus is small in size and contains only 10% to 20% of normal thymus tissue, and the parathyroid gland is also absent or underdeveloped. The number and distribution of plasma cells in peripheral lymphoid tissues are normal.

Differential diagnosis

Different from other primary and secondary immunodeficiency diseases, it can be identified according to clinical characteristics and laboratory assistant examinations.

Cardiac abnormality

Most patients have a left heart outflow tract malformation. Other lesions include right heart outflow tract malformations including pulmonary atresia and tetralogy of Fallot, right ventricular outflow tract, and pulmonary artery stenosis.

2. Hypocalcemia

Hand and foot convulsions caused by hypocalcemia usually occur within 24 to 48 hours after birth, and 1 patient diagnoses hypocalcemia for the first time at 5 years of age. In 40 cases of long-term follow-up, 26 cases of hypocalcemia were corrected, 4 cases died, and the remaining 10 patients continued to receive treatment. Hypocalcemia is particularly prominent during the first two weeks of life, but most are transient and relieve with age.

3. Facial features

Facial features include long face, spherical tip and narrow nose, cleft palate, flattened humerus, widened eye, squinted eyes, low lop ear with occlusion of the ear and dysplasia of the auricle and hypomandible. Other rare body abnormalities include microcephaly, short stature, slender toe, inguinal hernia, and scoliosis.

Repeated infection

Children with complete DiGeorge syndrome have immunodeficiency due to thymic dysplasia, often with 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 has increased, and neuropsychiatric problems have been paid attention to. Children with mild neuropsychiatric development and cognitive impairment. The majority of sick children had an 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.

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