22q11.2 Deletion Syndrome (Velocardiofacial Syndrome/DiGeorge Syndrome)
The syndrome described is 22q11.2 deletion syndrome, which encompasses the previously named velocardiofacial syndrome and DiGeorge syndrome 1.
Clinical Recognition
This constellation of features—congenital heart disease, long face, tubular nose, low-set ears, and bifid uvula—represents the classic presentation of 22q11.2 deletion syndrome (22q11.2DS). This is the most common microdeletion syndrome in humans, occurring in approximately 1 in 2148 live births 1.
Key Diagnostic Features
The syndrome presents with:
- Cardiac abnormalities: Primarily conotruncal defects (the most frequent cause of these malformations)
- Characteristic facial dysmorphology: Long face, tubular nose, low-set ears
- Palatal abnormalities: Bifid uvula, cleft palate, velopharyngeal insufficiency
- Speech/language deficits
- Learning and behavioral problems
- Recurrent infections (due to immune deficiency from thymic hypoplasia)
- Hypocalcemia (from parathyroid hypoplasia)
Historical Context
22q11.2DS was previously described under multiple clinical names that are now recognized as the same genetic condition:
- Velocardiofacial syndrome
- DiGeorge syndrome
- Conotruncal anomaly face syndrome
- Cayler cardiofacial syndrome
- A subset of Opitz G/BBB syndrome
Genetic Basis
The syndrome results from a deletion on the long arm of chromosome 22 at the 11.2 band, typically a 3 Mb deletion between low copy repeats LCR22A and LCR22D. This deletion encompasses multiple genes including TBX1, which is critical for cardiac and craniofacial development 1.
Diagnostic Approach
Confirm the diagnosis with chromosomal microarray or FISH (fluorescence in situ hybridization) testing targeting the 22q11.2 region 1. Clinical suspicion based on the phenotypic features you've described warrants immediate genetic testing, as early diagnosis enables:
- Comprehensive cardiac evaluation and management
- Immunological assessment (T-cell counts, vaccine response)
- Endocrine screening (calcium, parathyroid function)
- Multidisciplinary surveillance for associated morbidities
Clinical Significance
Recognition of this syndrome is critical because it carries significant morbidity across multiple organ systems requiring coordinated subspecialty care. The 2023 updated guidelines emphasize comprehensive evaluation and surveillance strategies to address the physical, cognitive, behavioral, and psychiatric manifestations that impact quality of life 1, 2.