ABSTRACT
22q11.2 microdeletion syndrome is a genetic syndrome caused by the deletion of 22q11.21-q11.23 in the proximal long arm microfragment of chromosome 22 for human. TBX1 belongs to the T-box family and is located in 22q11.2 of chromosome. Studies have shown that haploinsufficiency of TBX1 is the main cause of 22q11.2 microdeletion syndrome, which is of great significance for the appearance of its phenotype. Therefore, this paper reviews the research progress of TBX1 in the mechanism of cardiac disease, pulmonary artery phenotype, thymus development, pharyngeal and palatal development, lymphatic formation, and low proliferation of parathyroid tumors.
ABSTRACT
22q11.2 microdeletion syndrome is a genetic syndrome caused by the deletion of 22q11.21-q11.23 in the proximal long arm microfragment of chromosome 22 for human. TBX1 belongs to the T-box family and is located in 22q11.2 of chromosome. Studies have shown that haploinsufficiency of TBX1 is the main cause of 22q11.2 microdeletion syndrome, which is of great significance for the appearance of its phenotype. Therefore, this paper reviews the research progress of TBX1 in the mechanism of cardiac disease, pulmonary artery phenotype, thymus development, pharyngeal and palatal development, lymphatic formation, and low proliferation of parathyroid tumors.
ABSTRACT
Velocardiofacial syndrome (VCFS) is due to a microdeletion on chromosome region 22q11.2. Clinically, it is characterized by congenital anomalies and psychiatric and cognitive manifestations. The most common structural defects are congenital heart disease and palatal anomalies, both due to abnormal development of the pharyngeal pouches. Another less studied manifestation is abdominal wall hernias. Objective: To characterize the frequency and types of hernias in patients with VCFS, and their association with congenital cardiopathies and palatine abnormalities. Patients and Methods: 202 patients were evaluated by direct clinical examination and questionnaire about their phenotypic characteristics. Results were compared to those found in the literature. Results: Age range was 0.5 to 48.4 years old (mean 11.9 years), 50.4 percent were females. Twenty two percent of patients had abdominal wall hernias. Of these, 49.1 percent were inguinal and 40.3 percent, umbilical. Conclusion: Patients with VCFS have a higher incidence of abdominal hernias than general population, described as approximately 5 percent. This is another common manifestation of the syndrome, not attributable to defects in development of pharyngeal pouches and with unknown pathogenesis.
El síndrome velocardiofacial (SVCF) se debe a una microdeleción en la región cromosómica 22q11.2. Clínicamente, se caracteriza por anomalías congénitas y manifestaciones siquiátricas y cognitivas. Entre las malformaciones más comunes, están las cardiopatías congénitas y anomalías palatinas, por defectos en el desarrollo de las bolsas faríngeas. Otra manifestación menos estudiada son las hernias de la pared abdominal. Objetivo: Caracterizar la frecuencia y tipos de hernias en pacientes con SVCF y su asociación con cardiopatías congénitas y anomalías del paladar. Pacientes y Método: Evaluamos 202 pacientes mediante un examen clínico directo y un cuestionario sobre sus características fenotípicas. Comparamos los resultados con la información de la literatura. Resultados: El rango de edad fue de 0,5 a 48,4 años (media de 11,9 años), 50,4 por ciento de sexo femenino. El 22 por ciento de los pacientes presentó hernias de la pared abdominal. De estas, el 49,1 por ciento fueron inguinales y el 40,3 por ciento, umbilicales. La frecuencia de hernias en los pacientes con SVCF es significativamente mayor que la descrita para la población general, aproximadamente un 5 por ciento. Esta es una manifestación común del síndrome, que no es atribuible a defectos del desarrollo de las bolsas faríngeas y cuya patogenia no ha sido definida.
Subject(s)
Humans , Male , Female , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Heart Defects, Congenital/epidemiology , Hernia, Abdominal/epidemiology , DiGeorge Syndrome/epidemiology , Chile , Chromosome Deletion , Cleft Palate/epidemiology , Phenotype , Prevalence , DiGeorge Syndrome/geneticsABSTRACT
Conotruncal defects(CTD) is a kind of severe cardiovascular abnormality, which is the major cause of death in rinatal pelriod. Some researches suggest that CTD and 22q11 microdeletion had close relationship. In addition, HIRA gene is located in 22q11, which was speculated as a candidate gene in CTD.
ABSTRACT
We experienced a case of partial DiGeorge syndrome in a 35+5 week premature female infant presented with micrognathia, fish-shaped mouth, beaked nose, nasal regurgitation, obstructive sleep apnea, velopharyngeal insufficiency and late onset hypocalcemic seizures. The chromosome 22q11 microdeletion was found by the FISH method. The lab findings showed serum calcium level of 4.4 mg/dL, ionized calcium level of 0.49 mg/dL, phosphorous level of 7.5 mg/dL, magnesium level of 1.3 mg/dL and PTH-RIA level of <1 pq/mL. Initial treatment was done with 10% calcium gluconate infusion and magnesium sulfate followed by oral calcium gluconate and low phosphorous- formula milk feeding. The serum calcium level was normalized in 6 days. Nasal regurgitation, desaturation with obstructive sleep apnea continued. T-cell functions and numbers(CD 3, CD 4, CD 8)were decreased but Ig G/A/M levels were normal. No visible signs of thymus shadow were seen in either chest X-ray and chest MRI. Electrocardiography and echocardiography showed normal heart. Kidney ultrasonographby showed right side mild hydronephrosis. Neurosonography was normal but EEG showed electrical partial seizure. Hearing assessment by BERA showed mild to moderate hearing impairment. Velopharyngoplasty is scheduled for further treatment. A brief review of literature was made.