Here, we review the range of congenital heart defects and the molecular effects of CHD7 on cardiovascular development that lead to an over-representation of atrioventricular septal, conotruncal, and aortic arch defects in CHARGE syndrome.
CHARGE syndrome is linked to autosomal-dominant mutations in the CHD7 gene and results in a number of physiological and structural abnormalities, including heart defects, hearing and vision loss, and gastrointestinal (GI) problems.
The types of heart defects found in patients with CHD7 mutations are variable, with an overrepresentation of atrioventricular septal defect and outflow tract defect including aortic arch anomalies compared to nonsyndromic heart defects.
CHD7 plays an important role in cardiac development, given that we found a wide range of heart defects in 74% of a large cohort of patients with a CHD7 mutation.
CHD7 gene mutations were identified in 17 (71%) of 24 children clinically diagnosed to have CHARGE syndrome (C, coloboma of the iris or retina; H, heart defects; A, atresia of the choanae; R, retardation of growth and/or development; G, genital anomalies; and E, ear abnormalities).
Other congenital malformations commonly found in association with ocular coloboma (e.g. oesophageal fistulae and heart defects in CHARGE association) may also be VAD related.