single ventricle with truncus arteriosus in siblings

Common Arterial Trunk Associated with Functionally Univentricular Heart: Anatomical Study and Review of the Literature

Common arterial trunk (CAT) is a rare congenital heart disease that is commonly included into the spectrum of conotruncal heart defects. CAT is rarely associated with functionally univentricular hearts, and only few cases have been described so far. Here, we describe the anatomical characteristics of CAT associated with a univentricular heart diagnosed in children and fetuses referred to our institution, and we completed the anatomical description of this rare condition through an extensive review of the literature. The complete cohort ultimately gathered 32 cases described in the literature completed by seven cases from our unit (seven fetuses and one child). Four types of univentricular hearts associated with CAT were observed: tricuspid atresia or hypoplastic right ventricle in 16 cases, mitral atresia or hypoplastic left ventricle in 12 cases, double-inlet left ventricle in 2 cases, and unbalanced atrioventricular septal defect in 9 cases. Our study questions the diagnosis of CAT as the exclusive consequence of an anomaly of the wedging process, following the convergence between the embryonic atrioventricular canal and the common outflow tract. We confirm that some forms of CAT can be considered to be due to an arrest of cardiac development at the stages preceding the convergence.

Approach for in vivo delivery of CRISPR/Cas system: a recent update and future prospect

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) system provides a groundbreaking genetic technology that allows scientists to modify genes by targeting specific genomic sites. Due to the relative simplicity and versatility of the CRISPR/Cas system, it has been extensively applied in human genetic research as well as in agricultural applications, such as improving crops. Since the gene editing activity of the CRISPR/Cas system largely depends on the efficiency of introducing the system into cells or tissues, an efficient and specific delivery system is critical for applying CRISPR/Cas technology. However, there are still some hurdles remaining for the translatability of CRISPR/Cas system. In this review, we summarized the approaches used for the delivery of the CRISPR/Cas system in mammals, plants, and aquacultures. We further discussed the aspects of delivery that can be improved to elevate the potential for CRISPR/Cas translatability.

Efficient and high-fidelity base editor with expanded PAM compatibility for cytidine dinucleotide

Cytidine base editor (CBE), which is composed of a cytidine deaminase fused to Cas9 nickase, has been widely used to induce C-to-T conversions in a wide range of organisms. However, the targeting scope of current CBEs is largely restricted to protospacer adjacent motif (PAM) sequences containing G, T, or A bases. In this study, we developed a new base editor termed "nNme2-CBE" with excellent PAM compatibility for cytidine dinucleotide, significantly expanding the genome-targeting scope of CBEs. Using nNme2-CBE, targeted editing efficiencies of 29.0%-55.0% and 17.3%-52.5% were generated in human cells and rabbit embryos, respectively. In contrast to conventional nSp-CBE, the nNme2-CBE is a natural high-fidelity base editing platform with minimal DNA off-targeting detected in vivo. Significantly increased efficiency in GC context and precision were determined by combining nNme2Cas9 with rationally engineered cytidine deaminases. In addition, the Founder rabbits with accurate single-base substitutions at Fgf5 gene loci were successfully generated by using the nNme2-CBE system. These novel nNme2-CBEs with expanded PAM compatibility and high fidelity will expand the base editing toolset for efficient gene modification and therapeutic applications.

Precise, predictable multi-nucleotide deletions in rice and wheat using APOBEC-Cas9

Short insertions and deletions can be produced in plant genomes using CRISPR-Cas editors, but reliable production of larger deletions in specific target sites has proven difficult to achieve. We report the development of a series of APOBEC-Cas9 fusion-induced deletion systems (AFIDs) that combine Cas9 with human APOBEC3A (A3A), uracil DNA-glucosidase and apurinic or apyrimidinic site lyase. In rice and wheat, AFID-3 generated deletions from 5'-deaminated C bases to the Cas9-cleavage site. Approximately one-third of deletions produced using AFID-3 in rice and wheat protoplasts (30.2%) and regenerated plants (34.8%) were predictable. We show that eAFID-3, in which the A3A in AFID-3 is replaced with truncated APOBEC3B (A3Bctd), produced more uniform deletions from the preferred TC motif to the double-strand break. AFIDs could be applied to study regulatory regions and protein domains to improve crop plants.

Prenatal diagnosis of truncus arteriosus using multiplanar display in 4D ultrasonography

Prenatal diagnosis of truncus arteriosus with two-dimensional sonography requires expertise in fetal echocardiography. Indeed, truncus arteriosus shares with tetralogy of Fallot and pulmonary atresia with a ventricular septal defect (VSD) the sonographic finding of a single arterial trunk overriding a VSD. The diagnosis of truncus arteriosus can be confirmed when either the main pulmonary artery or its branches are visualized arising from the truncus itself. This requires sequential examination of multiple scanning planes and a process of mental reconstruction of their spatial relationships. The advantage of multiplanar imaging in three-dimensional and four-dimensional ultrasonography is that it allows for the simultaneous visualization of three orthogonal anatomic planes, which can be very important in diagnosing cardiac abnormalities. We report, first, a case of truncus arteriosus diagnosed in utero where the multiplanar display modality provided important insight into the differential diagnosis of this conotruncal anomaly, and then, review the diagnosis of truncus arteriosus on ultrasound.

Single ventricle with persistent truncus arteriosus as two rare entities in an adult patient: a case report

Introduction

Single ventricle and truncus arteriosus are both rare congenital cardiac syndromes with limited survival. Their occurrence together is extremely uncommon and prolonged survival is exceptionally rare. We present the case of a patient who had both of these defects with survival to age 45.

Case presentation

We describe the vase of a 45-year-old man with the unusual occurrence of two very rare congenital cardiac defects. He was found to have both truncus arteriosus and single ventricle with long survival. His history, clinical course, and anatomic findings are discussed along with the factors which may have contributed to his longevity, which is unique in the medical literature. His management reflected the state of medical knowledge at the time when he presented, and although alternate approaches may have been utilized if the patient presented today, this case does indicate the efficacy of the management options available at the time and place of the patient's contacts with the medical care system in Belarus. We discuss the findings, frequency, classification, and management of both of these congenital defects.

Conclusion

This case demonstrates that patients with very complex congenital cardiac disease may survive to adulthood, presenting challenges in both medical and surgical treatment. As the management of these patients is constantly evolving, and interventional techniques are improving, patients such as this with prolonged survival will be more common, with each case providing insights to future treatment. Challenges in management may include prior care provided in health care systems with limited resources.

Univentricular Heart

As early as 1699, Chemineau described a heart composed of 2 auricles but only 1 ventricle. 1 The univentricular heart has since fascinated the medical community. Unique in its complexity and scope, the univentricular heart has sparked intense debates about embryology and nomenclature, challenged our understanding of cardiovascular physiology and hemodynamics, and inspired some of the most creative surgical and interventional approaches in human history. The present report provides an overview of the nomenclature and classification of the univentricular heart, epidemiology and pathological subtypes, genetic factors, physiology, clinical features, diagnostic assessment, therapy, and postoperative sequelae. Although the present report touches on issues applicable to neonates and children with univentricular hearts, the focus is on information of interest and relevance to the adult cardiologist.

Persistent truncus arteriosus: pathologic anatomy in 54 cases

Fifty-four specimens of heart with persistent truncus arteriosus (PTA) were reviewed anatomically. According to the Collett-Edwards classification there were 28 examples of type I and 26 type II. The sex distribution was equal. The number of the truncal cusps ranged from one to four (42% tricuspid, 30% bicuspid, 24% quadricuspid, and 4% unicommissural). A unicommissural truncal valve has not been previously reported. In 72% of cases, the truncal valve leaflets were thickened or dysplastic. Two valves were stenotic. The truncus arteriosus originated from both ventricles equally in 42% of the cases, predominantly from the right ventricle in 42%, and predominantly from the left ventricle in 16% of the cases. In unoperated cases of PTA originating predominantly from the right ventricle, it appeared to us that usual operative correction might result in left ventricular outflow obstruction. Variations in coronary arterial origins and patterns were present in nearly half of the cases. A single coronary artery was observed in ten cases (18.5%). Stenosis of the ostium of one coronary artery was seen in each of four cases (7%). High posterior origin of the left coronary artery was observed in ten cases (18.5%). Among the associated cardiovascular anomalies, the most common were right aortic arch (36%) and interruption of the aortic arch (11%). Three cases with the latter condition exhibited crossed pulmonary arteries. Isolated cases with tricuspid atresia, vascular sling (left pulmonary artery arising from right pulmonary artery), and persistent common atrioventricular canal were encountered.

Persistent truncus arteriosus in monozygotic twins: case report and literature review

We report on a pair of monozygotic twins with persistent truncus arteriosus. They had no evident clinical signs of DiGeorge syndrome. Pathologic examination of the placenta and DNA analysis in chromosomes 7, 8, and 15 was consistent with monozygosity. Fluorescence in situ hybridization test was negative for chromosome 22q11 microdeletion. Family history revealed a female cousin with tetralogy of Fallot. The isolated presence of this conotruncal abnormality in monozygotic twins is extremely rare. The genetic considerations are discussed.

Truncus arteriosus associated with mitral atresia and a hypoplastic left ventricle

The association of truncus arteriosus with congenital left heart abnormalities is rare. We describe a case of truncus arteriosus associated with mitral atresia and a hypoplastic left ventricle. In 11 other patients diagnosed with truncus arteriosus, none had left heart hypoplasia. Despite the truncal root being primarily or entirely committed to the right ventricle, more right than left heart abnormalities have been found. This is in contrast to double-outlet right ventricle in which left heart abnormalities are more often associated.

Dizygotic twins concordant for truncus arteriosus

Persistent truncus arteriosus (TA) is an uncommon congenital cardiovascular malformation, which comprises between 0.4% and 4% of all congenital heart defects. Occurrence of TA in siblings has been reported infrequently. Twins concordant for isolated TA appear to have been reported only once previously. In this paper, we describe dizygotic twin females who were concordant for isolated TA.

Genetics of conotruncal malformations: review of the literature and report of a consanguineous kindred with various conotruncal malformations

Genetic predisposition in congenital heart disease is considered to be a component of multifactorial inheritance. Recently, monogenic inheritance in conotruncal malformations has been suggested. We describe a consanguineous kindred with various conotruncal malformations, the presence of which lends support to the idea that this spectrum of malformation is monogenically inherited. Theoretical background and experimental and clinical data are reviewed and discussed.

Occurrence of congenital heart defects in siblings of patients with univentricular heart and tricuspid atresia

Because of the rarity of univentricular heart and tricuspid atresia, no study of a large number of patients has been made to determine the empiric occurrence risks of a congenital heart defect in their siblings. A retrospective chart review was performed of 223 patients with univentricular heart and 113 with classic tricuspid atresia evaluated from 1982 to 1987. Thirty-four patients with univentricular heart and 17 with tricuspid atresia had no siblings and were excluded. Eleven of the total 388 siblings (2.8%) of the 189 patients with univentricular heart had a congenital heart defect. Of the siblings born after the index case of univentricular heart, 7 of 169 (4.1%) had a congenital heart defect. Two of the 210 siblings (1.0%) of the 96 patients with tricuspid atresia had a congenital heart defect. The patients with univentricular heart were subdivided into 4 groups: (1) double-inlet left ventricle; (2) complex univentricular heart with single or common inlet, or with a ventricle of common or right ventricular morphology; (3) complex univentricular heart with asplenia; and (4) complex univentricular heart with polysplenia. One of the 202 siblings (0.5%) of the 102 patients with double-inlet left ventricle had a congenital heart defect, compared with 7 of the 140 siblings (5.0%) of the 69 patients with complex univentricular heart, 1 of the 29 siblings (3.4%) of the 14 patients with complex univentricular heart and asplenia, and 2 of the 7 siblings (28.6%) of the 4 patients with complex univentricular heart and polysplenia.(ABSTRACT TRUNCATED AT 250 WORDS)

Successful diagnosis and surgical treatment of single ventricle, truncus arteriosus

The association of single ventricle and truncus arteriosus is rare. We present the successful surgical palliation of a patient who echocardiographically and angiographically has a truncus arteriosus type I and single left ventricle. At operation, the main pulmonary artery was dissected off the truncus arteriosus, and a 4-mm polytetrafluoroethylene graft was placed from the ascending aorta to the left pulmonary artery. The patient is currently 13 months old and growing well.

Cardiac malformations in relatives of children with truncus arteriosus or interruption of the aortic arch

Familial recurrence risks for congenital cardiac malformations have been estimated at 1 to 4%, but little is known of recurrence risks for uncommon congenital cardiac malformations. This study determined the incidence of congenital cardiac malformations in relatives of patients with either truncus arteriosus (TA) or interruption of the aortic arch (IAA) seen between 1955 and 1985. Prior to this study, only 2 cases of IAA in siblings had been reported and the recurrence risk of TA had been estimated at 1.2%. In the families of 36 index cases of IAA, there were 98 siblings, 2 with congenital cardiac malformations (2.1%). All recurrences were in IAA type B families. Single cases of congenital cardiac malformations were found in second- and third-degree relatives and 2 cases in more distant relatives. In the families of 49 index cases of TA, there were 106 siblings, 7 with congenital cardiac malformations (6.6%). Two had TA, 3 had other conotruncal anomalies and 2 had other congenital cardiac malformations. Two parents had congenital cardiac malformations, 1 with TA and 1 with conotruncal malformation. Among second- and third-degree relatives, 7 had congenital cardiac malformations (5 were conotruncal, including 1 half sibling). Among greater than third-degree relatives, 3 had congenital cardiac malformations. Thus, in IAA, the recurrence rate of congenital cardiac malformations (2.1%) was higher than expected and could be related to the etiology of IAA type B as a conotruncal malformation. In TA, the recurrence rate of congenital cardiac malformations was 6.6%, higher than previously reported. When TA was complex the recurrence risk was higher (13.6%). These findings must be taken into consideration for satisfactory genetic counseling.