Search
DiGeorge syndrome; velocardiofacial syndrome; pharyngeal pouch syndrome
Congenital anomaly of the 3rd & 4th pharyngeal pouches. Absence of thymus & parathyroids.
Pathology:
1) absence of thymus & parathyroids
2) deformities of the ear, nose, mouth
3) structural & functional palate anomalies
4) facial anomalies
5) cardiac
a) interrupted aortic arch
b) tetralogy of Fallot
c) persistent truncus arteriosus 6 immunodeficiency
Genetics:
- most cases result from a deletion of chromosome 22q11.2 (the DiGeorge syndrome chromosome region)
- associated with defects in TBX1
- haploinsufficiency of the TBX1 gene is responsible for most of the physical malformations present in DiGeorge syndrome & velocardiofacial syndrome
- these two syndromes represent two forms of clinical expression of the same entity manifesting at different stages of life
- may be role for HIRA, LZTR1, DGCR13, GSC2, DVL1L1
Clinical manifestations:
- congenital heart defects
- immunodeficiency secondary to thymic hypoplasia
- hypocalcemia secondary to hypoparathyroidism due to parathyroid gland hypoplasia
- deformities of the ear, nose, mouth, palate
Laboratory:
- hypocalcemia
Related
Shprintzen syndrome; velocardiofacial syndrome
General
developmental disorder syndrome (multisystem disorder)
genetic syndrome (multisystem disorder)
hypoparathyroidism
immunodeficiency; immunodeficiency syndrome
Database Correlations
OMIM correlations
References
- Mendelian Inheritance in Man (1990) MIM#188400
- Harrison's Principles of Internal Medicine, 13th ed.
Isselbacher et al (eds), McGraw-Hill Inc. NY, 1994, pg 1038