De novo large rare copy-number variations contribute to conotruncal heart disease in Chinese patients

Unique missing or repeated sequences of the genome often contribute to congenital heart defects in Chinese patients. A team led by Brian Chung from the University of Hong Kong looked for copy number variations (CNVs) in 116 Chinese patients with malformations of the outflow tracts of the heart. They focused only on deletions or duplications that were over 500,000 DNA letters long and found in less than 1% of individuals from a larger cohort of Caucasian and Singaporean individuals with the same heart anomalies. The authors identified 10 such CNVs, three of which had never been documented clinically and occurred in gene regions linked to cardiac development. The research suggests that East Asians and Europeans harbor different CNVs responsible for congenital heart disease, but larger studies are needed to confirm the ethnic differences.