In December 2021, a 24-year-old female was admitted to the hospital because of intermittent chest tightness and suffocation for 6 years, followed by 3 months with no medical history. The results of the medical examination were as follows: temperature 36.8 C, pulse 72 times/min, respiratory rate 16 times/min, and blood pressure 113/76 mmHg. More results included clear, stable breathing, coarse breath sounds in both lungs, no rale or wet rale, no uplift in the precardiac area, strong heart sound, consistent heart rhythm (HR 72 beats/min), no murmur in the auscultation area of each valve, flat and soft abdomen, no tenderness, internal rotation malformation of both upper limbs, no external rotation, and no edema in either of the lower limbs.
A bilateral elbow wrist joint examination demonstrated the partial fusion of the bones at the proximal end of both the ulna and radius, widening of the radial ulnar joint at the distal end, and poor alignment, suggesting congenital dysplasia in the wrist and elbow joints (Figure 1A). Cardiac color ultrasonography showed no abnormalities in the cardiac structure or function in the resting state (left ventricular ejection fraction = 65%). Outpatient coronary computed tomography angiography and angiography after admission revealed that her left coronary artery originated from the right coronary sinus and the slender left coronary artery was contorted between the aorta and the pulmonary artery (Figures 1B, C). In the cardiac systolic movement, severe stenosis appeared in the left coronary artery opening; however, no obvious stenosis was observed in the right coronary artery, left descending artery, or left circumflex artery. Resting and adenosine load-gated myocardial perfusion imaging revealed no typical reversible abnormal perfusion in the left ventricular myocardium and showed that the left ventricular cardiac function index was normal (Figure 1D).
The transient heart rate increased and chest tightness appeared after admission. An electrocardiogram examination suggested a high sinus heart rate, HR 123 beats/min, and ST segment depression. A three-dimensional printed model was used to determine the appropriate surgical approach (Figure 1E). Midline thoracotomy was performed by cardiopulmonary bypass. We found that the left main trunk was deformed between the ascending aorta and the main pulmonary artery and arose from the right coronary sinus; therefore, correction surgery for coronary artery malformation was performed to reconstruct the left main trunk. On the first day after surgery, the patient had a heart rate of 130 beats/min and no other symptoms, such as chest tightness, appeared. A coronary computed tomography angiographic examination was performed again after surgery, which demonstrated that the left main trunk had returned to a normal shape.
To investigate the genetic etiology, we performed mutation and SNP analyses of the patient's family using SAMtools and ANNOVAR (Novogene, Beijing, China). The screened mutations and SNPs were correlated using ClinVar (https://ncbi.nlm.nih.gov/clinvar/), which indicated that the patient inherited a base T (reference C) at dbSNP ID rs883079 from her mother and base C (reference T) at dbSNP ID rs10850326 from her father, both of which belong to the 3'-UTR of the TBX5 gene (Table 1). However, no alterations in TBX5 expression or SNPs in other exons were found. The patient also inherited a SALL4 SNP in the exon area from both her father and mother. We identified 578 exons, 498 3'-UTRs, and 346 5'-UTR mutations in the patient, including the female urogenital genes PKD1, SON, and BMPR1B, as well as the reproduction-related genes TEKT2, TEKT4, COL11A1, ANKRD11, LEMD3, and SPTB (Supplementary Materials: Raw Data).
We explored the effects of TBX5 on the HL-1 cell line with TBX5 knockdown via transfection of small interfering RNAs (Ubigene, Guangzhou, China; Figure 2A). Quantitative polymerase chain reaction analysis demonstrated that the expression of TEKT2, TEKT4, and SPTB decreased after TBX5 knockdown (Figure 2B), and chromatin immunoprecipitation analysis further revealed that TBX5 binds to TEKT2, TEKT4, and SPTB promoter regions to promote gene transcription (Figures 2C, D; Table 2). We performed sequence alignment between the TBX5 3'-UTR regions, including rs883079 and rs10850326, and microRNAs (miRNA), including hsa-miR-98-5p, hsa-miR-10a, hsa-miR-10b, and hsa-miR-182-5p. All four miRNAs could bind to the TBX5 3'-UTR that included rs883079, while only hsa-miR-10a and hsa-miR-182-5p could bind to the region that included rs10850326, demonstrating that the increased binding of miRNAs and TBX5 3'-UTR in HOS further decreased TBX5 expression (Figure 2E). These SNPs and familial mutations may be associated with the differential expression of TBX5 (Figure 2F).