NeurometPlus

Incidence

22q11.2 deletion syndrome, also known as DiGeorge anomaly, DiGeorge Syndrome, Velo-Cardio-Facial syndrome, Shprintzen syndrome, conotruncal anomaly face syndrome, Congenital Thymic Aplasia, Strong Syndrome, Thymic hypoplasia, and DiGeorge anomaly is a syndrome caused by the deletion of a small piece of chromosome 22. The deletion occurs near the middle of the chromosome at a location designated q11.2 i.e., on the long arm of one of the pair of chromosomes 22. It has a prevalence estimated at 1:4000. Review familial DiGeorge and velocardiofacial syndromes incidences. Usually de novo deletions.

Clinical Characteristics

The signs and symptoms of 22q11 deletion syndrome are so varied that different groupings of its features were once regarded as separate conditions. These original classifications included velo-cardio-facial syndrome, Shprintzen syndrome, DiGeorge syndrome, Sedlackova syndrome and conotruncal anomaly face syndrome. All are now understood to be presentations of a single syndrome. Deletion of the long arm of chromosome 22 with variable dysmorphic features consisting of a round face, almond-shaped palpebral fissures, bulbous nose, malformed ears, hypotonia, short stature, mental retardation, and other anomalies. Deletion of the proximal long arm of chromosome 22 (22q11) has been associated with familial DiGeorge and velocardiofacial syndromes and terminal deletion was found in Goldenhar syndrome. Abnormalities of chromosome 22 are also suspected of being involved in the etiology of neoplastic diseases. Medical students have used the mnemonic CATCH to describe DiGeorge syndrome (Cardiac abnormality, especially Fallot\'s tetralogy, Abnormal facies, Thymic aplasia, Cleft palate, Hypocalcemia).

Precipitants

None

Provocation Tests

None

Diagnostic Procedures

Karyotype. Chromosome 22q deletion. FISH. Review familial DiGeorge and velocardiofacial syndromes diagnosis.