Mutation Analysis of TBX1 in Children with Conotruncal Heart Anomalies

Excerpt

To the Editor: Conotruncal heart anomalies (CTA) are structural malformations involving the outflow tract. While the exact incidence of CTA in India is not known, it remains the most common type of structural birth defect with a major impact on pediatric morbidity and mortality. While most CTA are sporadic, a few are associated with genetic syndromes; the 22q11 deletion syndrome (22q11.2DS) being the predominate one. The CTA related to the 22q11.2DS are usually associated with a common 3 Mb or 1.5 Mb proximally deleted region, both of which include the TBX1 gene. However, mutations of the TBX1 gene have also been reported in patients who do not have the 22q11.2 deletion but present with CTA. The TBX1 gene encodes a transcription factor of the T-box family and mouse models have demonstrated that TBX1 haploinsufficiency cause cardiac outflow tract lesions. …