Variants of the promoter of MYH6 gene in congenital isolated and sporadic patent ductus arteriosus: case-control study and cellular functional analyses.

Patent ductus arteriosus (PDA) is a common form of congenital heart disease. The MYH6 gene has important effects on cardiovascular growth and development, but the effect of variants in the MYH6 gene promoter on ductus arteriosus is unknown. DNA was extracted from blood samples of 721 subjects (428 patients with isolated and sporadic PDA and 293 healthy controls) and analyzed by sequencing for MYH6 gene promoter region variants. Cellular function experiments with three cell lines (HEK-293, HL-1, and H9C2 cells) and bioinformatics analyses were performed to verify their effects on gene expression. In the MYH6 gene promoter, 11 variants were identified. Four variants were found only in patients with PDA and 2 of them (g.3434G>C and g.4524C>T) were novel. Electrophoretic mobility shift assay showed that the transcription factors bound by the promoter variants were significantly altered in comparison to the wild-type in all three cell lines. Dual luciferase reporter showed that all the 4 variants reduced the transcriptional activity of the MYH6 gene promoter (P < 0.05). Prediction of transcription factors bound by the variants indicated that these variants alter the transcription factor binding sites. These pathological alterations most likely affect the contraction of the smooth muscle of ductus arteriosus, leading to PDA. This study is the first to focus on variants at the promoter region of the MYH6 gene in PDA patients with cellular function tests. Therefore, this study provides new insights to understand the genetic basis and facilitates further studies on the mechanism of PDA formation.

[Research progress of genetic research on Char syndrome].

Char syndrome is a rare autosomal dominant genetic disorder characterized by patent ductus arteriosus, facial dysmorphism, and dysplasia of fingers/toes. It may also be associated with multiple papillae, dental dysplasia, and sleep disorders. TFAP2B has proven to be a pathogenic gene for neural crest derivation and development, and several variants of this gene have been identified. Bone morphogenetic protein signaling plays an important role in embryonic development by participating in limb growth and patterning, and regulation of neural crest cell development. TFAP2B is an upstream regulatory gene for bone morphogenetic proteins 2 and 4. Variants of the TFAP2B gene may lead to abnormal proliferation of neural crest cells by affecting the expression of bone morphogenetic proteins, resulting in multiple organ dysplasia syndrome. In addition, TFAP2B variants may only lead to patent ductus arteriosus instead of typical Char syndrome.

[Clinical characteristics and genetic analysis of a child with Char syndrome caused by TFAP2B gene variant].

OBJECTIVE: To explore the clinical features and genetic etiology of a child with Char syndrome. METHODS: A child who was presented at the Department of Child Health, Henan Children's Hospital in February 2022 was selected as the study subject. Clinical data of the child was collected, and peripheral blood samples of the child and her parents were collected for the extraction of genomic DNA. Whole exome sequencing was carried out, and candidate variants were verified by Sanger sequencing and bioinformatic analysis. RESULTS: The child had mainly manifested facial dysmorphism, patent ductus arteriosus, growth retardation, curving of fifth fingers and middle toes. Whole exome sequencing revealed that she has harbored a heterozygous c.944A>C (p.Glu315Ala) variant of the TFAP2B gene, which was verified to be de novo by Sanger sequencing. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was rated to be likely pathogenic (PM1+PM2_Supporting+PM6+PP3). CONCLUSION: The heterozygous c.944A>C (p.Glu315Ala) variant of the TFAP2B gene probably underlay the Char syndrome in this child. Above finding has expanded the mutational and phenotypic spectra of the TFAP2B gene, which has facilitated early identification and diagnosis of Char syndrome.

Whole-exome sequencing of pathogenic genes in a family with congenital heart disease: A case report.

RATIONALE: Congenital heart disease (CHD) is the most common birth defect and an important cause of noninfectious deaths in infants and children. It has high prevalence globally, placing an enormous burden on society and families. Studies of individuals with hereditary or sporadic CHD have provided strong evidence for its genetic basis. The aim of this study was to identify causative gene variants in a Chinese family with congenital heart disease. PATIENT CONCERNS AND DIAGNOSES: Three generations of a CHD family were recruited. Proband III.9 was diagnosed with congenital heart disease at age 11 months, and the echocardiogram showed arterial ductus arteriosus, with a left-to-right shunt at the level of the arteries. Precedent III.10 was a twin of Proband III.9 who was diagnosed with congenital heart disease at age 11 months, in whom the echocardiogram revealed an arterial ductus arteriosus, an unenclosed patent ductus arteriosus, and a left to right shunt at the level of the arteries (second figure). III.8 was diagnosed with congenital heart disease at age 15, but echocardiography in this study showed no abnormalities. No cardiac abnormalities were detected in any of his parents, grandparents, or maternal grandparents. We performed whole-exome sequencing on CHD sufferers and their unexpressing family members to investigate the genetic causes of CHD in this family line. Exome sequencing identified 4 mutation sites in this family line. The variant c.3245A>G (p.His1082Arg) of the AMER1 gene was consistent with concomitant X-chromosome recessive inheritance, the variant c.238G>C (p.Val80Leu) of the KCNE1 gene was consistent with autosomal accessory inheritance, and the other 2 variants did not conform to the law of the mode of inheritance of the disease. OUTCOMES: The first identified variant, c.3245A>G (p.His1082Arg) of the AMER1 gene, with X-chromosome recessive inheritance, and the variant c.238G>C (p.Val80Leu) of the KCNE1 gene, which has been reported as autosomal dominant, may be the causative agent of CHD in this family line. These findings broaden the genetic scope of congenital heart disease and could help in the development of targeted drugs for the treatment of congenital heart disease.

Complex genotype-phenotype correlation of MYH11: new insights from monozygotic twins with highly variable expressivity and outcomes.

BACKGROUND: Thoracic aortic aneurysm/dissection (TAAD) and patent ductus arteriosus (PDA) are serious autosomal-dominant diseases affecting the cardiovascular system. They are mainly caused by variants in the MYH11 gene, which encodes the heavy chain of myosin 11. The aim of this study was to evaluate the genotype-phenotype correlation of MYH11 from a distinctive perspective based on a pair of monozygotic twins. METHODS: The detailed phenotypic characteristics of the monozygotic twins from the early fetal stage to the infancy stage were traced and compared with each other and with those of previously documented cases. Whole-exome and Sanger sequencing techniques were used to identify and validate the candidate variants, facilitating the analysis of the genotype-phenotype correlation of MYH11. RESULTS: The monozygotic twins were premature and presented with PDA, pulmonary hypoplasia, and pulmonary hypertension. The proband developed heart and brain abnormalities during the fetal stage and died at 18 days after birth, whereas his sibling was discharged after being cured and developed normally post follow-up. A novel variant c.766 A > G p. (Ile256Val) in MYH11 (NM_002474.2) was identified in the monozygotic twins and classified as a likely pathogenic variant according to the American College of Medical Genetics/Association for Molecular Pathology guidelines. Reviewing the reported cases (n = 102) showed that the penetrance of MYH11 was 82.35%, and the most common feature was TAAD (41.18%), followed by PDA (22.55%), compound TAAD and PDA (9.80%), and other vascular abnormalities (8.82%). The constituent ratios of null variants among the cases with TAAD (8.60%), PDA (43.8%), or compound TAAD and PDA (28.6%) were significantly different (P = 0.01). Further pairwise comparison of the ratios among these groups showed that there were significant differences between the TAAD and PDA groups (P = 0.006). CONCLUSION: This study expands the mutational spectrum of MYH11 and provides new insights into the genotype-phenotype correlation of MYH11 based on the monozygotic twins with variable clinical features and outcomes, indicating that cryptic modifiers and complex mechanisms beside the genetic variants may be involved in the condition.

Comparative Analysis of Machine Learning Algorithms Evaluating the Single Nucleotide Polymorphisms of Metabolizing Enzymes with Clinical Outcomes Following Intravenous Paracetamol in Preterm Neonates with Patent Ductus Arteriosus.

AIMS: Pharmacogenomics has been identified to play a crucial role in determining drug response. The present study aimed to identify significant genetic predictor variables influencing the therapeutic effect of paracetamol for new indications in preterm neonates. BACKGROUND: Paracetamol has recently been preferred as a first-line drug for managing Patent Ductus Arteriosus (PDA) in preterm neonates. Single Nucleotide Polymorphisms (SNPs) in CYP1A2, CYP2A6, CYP2D6, CYP2E1, and CYP3A4 have been observed to influence the therapeutic concentrations of paracetamol. OBJECTIVES: The purpose of this study was to evaluate various Machine Learning Algorithms (MLAs) and bioinformatics tools for identifying the key genotype predictor of therapeutic outcomes following paracetamol administration in neonates with PDA. METHODS: Preterm neonates with hemodynamically significant PDA were recruited in this prospective, observational study. The following SNPs were evaluated: CYP2E1*5B, CYP2E1*2, CYP3A4*1B, CYP3A4*2, CYP3A4*3, CYP3A5*3, CYP3A5*7, CYP3A5*11, CYP1A2*1C, CYP1A2*1K, CYP1A2*3, CYP1A2*4, CYP1A2*6, and CYP2D6*10. Amongst the MLAs, Artificial Neural Network (ANN), C5.0 algorithm, Classification and Regression Tree analysis (CART), discriminant analysis, and logistic regression were evaluated for successful closure of PDA. Generalized linear regression, ANN, CART, and linear regression were used to evaluate maximum serum acetaminophen concentrations. A two-step cluster analysis was carried out for both outcomes. Area Under the Curve (AUC) and Relative Error (RE) were used as the accuracy estimates. Stability analysis was carried out using in silico tools, and Molecular Docking and Dynamics Studies were carried out for the above-mentioned enzymes. RESULTS: Two-step cluster analyses have revealed CYP2D6*10 and CYP1A2*1C to be the key predictors of the successful closure of PDA and the maximum serum paracetamol concentrations in neonates. The ANN was observed with the maximum accuracy (AUC = 0.53) for predicting the successful closure of PDA with CYP2D6*10 as the most important predictor. Similarly, ANN was observed with the least RE (1.08) in predicting maximum serum paracetamol concentrations, with CYP2D6*10 as the most important predictor. Further MDS confirmed the conformational changes for P34A and P34S compared to the wildtype structure of CYP2D6 protein for stability, flexibility, compactness, hydrogen bond analysis, and the binding affinity when interacting with paracetamol, respectively. The alterations in enzyme activity of the mutant CYP2D6 were computed from the molecular simulation results. CONCLUSION: We have identified CYP2D6*10 and CYP1A2*1C polymorphisms to significantly predict the therapeutic outcomes following the administration of paracetamol in preterm neonates with PDA. Prospective studies are required for confirmation of the findings in the vulnerable population.

Fechamento do Canal Arterial Persistente Tipo Janela Com o Oclusor Septal AMPLATZER® / Percutaneous Closure of Window-Type Patent Ductus Arteriosus With the AMPLATZERTM Septal Occluder

Há vários anos, a oclusão percutânea do canal arterial persistente é uma técnica factível e eficaz na maioria das variantes morfológicas descritas por Krishenko. O tipo B, em janela, caracterizado por ser curto, permanece um desafio, devido ao maior risco de embolizações das próteses e das oclusões incompletas. Descrevemos aqui o uso bem-sucedido de oclusores septais AMPLATZER® em três pacientes com canal arterial em janela, dois casos tratados com dispositivos de 5 mm e um com o de 7 mm. O dispositivo AMPLATZER® desenhado para a oclusão da comunicação interatrial mostrou-se eficaz para o tratamento percutâneo dessa variante morfológica de canal arterial persistente.

For several years the percutaneous closure of patent ductus arteriosus has been a reliable and effective technique for most of the morphologic variants described by Krichenko. Type B, or window-type, patent ductus arteriosus remains a challenge due to the higher risk of device embolizations and incomplete occlusions. We report the successful use of AMPLATZERTM septal occluder in three patients with window-type patent ductus arteriosus, two cases treated with a 5-mm device and one case with a 7-mm device. The AMPLATZERTM device designed for the occlusion of atrial septal defects is effective for the percutaneous treatment of this morphological variant of patent ductus arteriosus.