DiGeorge TBX1 / 22q13.3 Combination LPU014

DiGeorge, Velocardiofacial (VCFS), and Conotruncal Anomaly Face syndromes are characterised by microdeletions in band 22q11.2. They share the phenotypic features covered by the acronym CATCH22 (cardiac defects; abnormal facies; thymic hypoplasia; cleft palate; hypocalcaemia). The incidence of these deletions is around 1:5000 making it one of the most common paediatric genetic defects. The 2 Mb DiGeorge Critical Region is disrupted in up to 90% of patients, whilst a minimal critical region of 480-575 Kb which contains several genes including the T-box transcription factor -TBX1, a key candidate for the aortic arch malformations and anomalies related to pharyngeal apparatus and ear development seen in DGS. In addition, TBX1 may play a role in behaviour. About 35% patients with DiGeorge develop psychiatric disorders, mainly schizophrenia and bipolar disorder.

The 22q subtelomere specific probe can be used to detect deletions involved in the 22q13.3 Deletion Syndrome. The probe contains the ProSAP2/SHANK3 gene, coding for a structural protein of the postsynaptic density of excitation synapses and expressed in the cortex and cerebellum. This gene is proposed to be a good candidate gene for the 22q13.3 Deletion Syndrome.

To provide a control probe for DiGeorge probe and to add value for the customer, Cytocell has included an additional probe for a completely separate disorder, 22q13.3 Deletion syndrome. The DiGeorge probe mix acts as a control for 22q13.3 and vice versa, providing two probes in one test, negating the need to keep two tubes of these relatively rare disorders in stock in customer's laboratories.