Endocardial Coronary Artery: A Rare Congenital Coronary Anomaly

SOX17 loss-of-function variation underlying familial congenital heart disease

As the most prevalent form of human birth defect, congenital heart disease (CHD) contributes to substantial morbidity, mortality and socioeconomic burden worldwide. Aggregating evidence has convincingly demonstrated that genetic defects exert a pivotal role in the pathogenesis of CHD, and causative mutations in multiple genes have been causally linked to CHD. Nevertheless, CHD is of pronounced genetic heterogeneity, and the genetic components underpinning CHD in the overwhelming majority of patients remain obscure. In this research, a four-generation consanguineous family suffering from CHD transmitted in an autosomal dominant mode was recruited. By whole-exome sequencing and bioinformatics analyses as well as Sanger sequencing analyses of the family members, a new heterozygous SOX17 variation, NM_022454.4: c.553G > T; p.(Glu185*), was identified to co-segregate with CHD in the family, with complete penetrance. The nonsense variation was neither detected in 310 unrelated healthy volunteers used as controls nor retrieved in such population genetics databases as the Exome Aggregation Consortium database, Genome Aggregation Database, and the Single Nucleotide Polymorphism database. Functional assays by utilizing a dual-luciferase reporter assay system unveiled that the Glu185*-mutant SOX17 protein had no transcriptional activity on its two target genes NOTCH1 and GATA4, which have been reported to cause CHD. Furthermore, the mutation abrogated the synergistic transactivation between SOX17 and NKX2.5, another established CHD-causing transcription factor. These findings firstly indicate SOX17 loss-of-function mutation predisposes to familial CHD, which adds novel insight to the molecular mechanism of CHD, implying potential implications for genetic risk appraisal and individualized prophylaxis of the family members affected with CHD.

Intra-Right Ventricle Course of the Coronary Arteries on Computed Tomography Angiography

BACKGROUND

The clinical relevance and anatomic characteristics of intracavitary coronary arteries coursing within the right ventricle (RV) are largely unknown.

OBJECTIVES

The aim of our study was to assess the clinical and computed tomographic characteristics of patients diagnosed with intracavitary coronary arteries coursing within RV (intra-RV coronaries).

METHODS

Electronic records from a single high-volume cardiac center were retrospectively screened for the presence of intra-RV coronaries among consecutive patients who underwent coronary computed tomography angiography (coronary CTA) from 2008 to 2019.

RESULTS

Overall, 31,748 coronary CTA reports were evaluated, and 17 subjects with intra-RV coronaries were identified. None of these patients was referred for subsequent invasive coronary angiography. One patient underwent coronary artery bypass grafting, 1 patient had a history of percutaneous coronary intervention, and 1 patient had a concomitant coronary anomaly: left circumflex coronary artery originating from the right coronary artery. All of the involved coronaries (n = 17) were the left anterior descending coronary arteries (LADs). Typical segmental coronary course within RV was along the border between free RV wall and interventricular septum (beneath interventricular groove), often within trabeculae carneae of the RV. Only the midsegment and distal segment of the LAD traversed within the RV. The mean ± SD distance from the aorta to the coronary entrance into the RV was 74.5 ± 17.1 mm, whereas the mean ± SD intra-RV coronary length was 25.1 ± 14.0 mm.

CONCLUSIONS

Intra-RV course of the coronaries in an adult CTA population is an infrequent anatomical variant involving LAD. It may require additional attention during interventional and surgical interventions.