Biallelic TYR and TKFC variants in Egyptian patients with OCA1 and new expanded TKFC features.

BACKGROUND: Oculocutaneous albinism type1 (OCA1) is caused by the TYR gene's homozygous and compound heterozygous variants. TKFC gene variants cause triokinase & FMN cyclase deficiency syndrome with variable multisystemic disorders. OBJECTIVES: To determine the potential disease-causing variants in two deceased patients presenting atypical OCA1 features by demonstrating three generations for a single family. The two deceased neonates had severe skeletal abnormalities and fatal hypertrophic cardiomyopathy. We also explored the potential mechanisms for the causative relationship between TKFC and multisystem disorders. PATIENTS AND METHODS: Due to the new emerging symptoms that weren't reported before with the TYR gene, the following methods were performed: Sanger sequencing for the TYR gene, followed by whole exome sequencing, co-segregation, and computational analyses. RESULTS: Extensive parental consanguinity was found, and consequently an autosomal recessive mode of inheritance was prioritized. Upon performing sequencing and segregation data, the following has been confirmed: positive co-segregation of nonsense homozygous NM_000372.5:c.346C > T p.(Arg116*) variant in TYR gene and multisystem disease-missense homozygous NM_015533.4:c.598G > A p.(Val200Ile) variant in TKFC gene in the two affected index patients who deceased due to hypertrophic cardiomyopathy. Using computational analysis, we found that c.598G > A p.(Val200Ile) pathogenicity has led to the failure of L2-K1 active site closure due to the potential differential fluctuation between valine and isoleucine residues. Subsequently, disruption of endogenous DHA phosphorylation was found. Two potential mechanisms exploring the causative relationship between TKFC gene and multisystem disorders have been suggested. CONCLUSIONS: This study presented a first family with the co-existence of biallelic variants in TYR and TKFC genes associating severe skeletal abnormalities and lethal hypertrophic cardiomyopathy. Neither of these genes would have been pursued in the standard genetic counseling. Such discovery is paving the way for more efficient genetic counseling. Comparing TKFC results with literature data showed that our relevant expanded TKFC variant is the 3rd worldwide.

Staged Percutaneous Management of Pulmonary Atresia and Intact Interventricular Septum: Stretching the Limits.

Aims: Pulmonary atresia with intact ventricular septum (PA/IVS) can be treated by catheter-based interventions and complemented by various surgical procedures. We aim to determine a long-term treatment strategy to enable patients to be surgery free, depending solely on percutaneous interventions. Methods and Results: We selected five patients from among a cohort of patients with PA/IVS treated at birth with radiofrequency perforation and dilatation of the pulmonary valve. Patients had reached a pulmonary valve annulus of 20 mm or larger on their biannual echocardiographic follow-up, with right ventricular dilatation. The findings, together with the right ventricular outflow tract and pulmonary arterial tree, were confirmed by multislice computerised tomography. Based on the angiographic size of the pulmonary valve annulus, all patients were successfully implanted with either Melody® or Edwards® pulmonary valves percutaneously, regardless of their small weights and ages. No complications were encountered. Conclusion: We managed to stretch the age and weight limitations for performing percutaneous pulmonary valve implantation (PPVI): interventions were attempted whenever a pulmonary annulus size of >20 mm was reached, which was rationalised by the prevention of progressive right ventricular outflow tract dilatation and accommodating valves between 24 and 26 mm, which is enough to sustain a normal pulmonary flow in adulthood.

Safety of Occlutech Septal Occluder ACCELL Flex II for Transcatheter Closure of Secundum Atrial Septal Defects in Children: A Long-Term Follow-Up.

OBJECTIVES: To assess the long-term safety and efficacy of the Occlutech® ACCELL® Flex II device used for atrial septal defect (ASD) closure. This device differs from the regular device by having two very thin patches that are made of polyethylene terephthalate (PET). These patches enhance faster sealing of the defect. BACKGROUND: Transcatheter closure has become the method of choice to manage most patients with secundum ASDs. There are different types of devices. The regular Occlutech device used to close an ASD is called the Occlutech Figulla Flex II. A newer modification of this device (Occlutech® ACCELL® Flex II) has been designed to eliminate/reduce thrombus formation and to enhance faster sealing. METHODS: Thirty patients were followed up after occlusion of secundum ASD using the Occlutech® ACCELL® Flex II Device. The follow-up period ranged from 5.2-5.5 years with median of 5.3 years. Detailed history and full clinical examination, twelve-lead electrocardiogram (ECG), plain chest radiograph, and full 2D transthoracic echocardiography (TTE) were performed at discharge, at one month, six months, and yearly thereafter. RESULTS: The mean age of the study group at the last follow-up was 10.4 ± 4.6 years, with 63.3% (nineteen patients) females. There were no residual shunts or complications encountered immediately after the procedure and at the latest follow-up. CONCLUSION: This study confirmed the transcatheter closure (TCC) of secundum ASDs using the Occlutech® ACCELL® Flex II device to be safe and effective with no complications detected in children and adolescents.

Rheology of right ventricular outflow tract obstruction: sub-pulmonary membrane developing months after primary intervention to treat pulmonary atresia with intact interventricular septum.

Isolated sub-pulmonary membrane is a rare condition, the origin of which has been debatable. Transcatheter treatment of pulmonary valve atresia with intact interventricular septum by radiofrequency perforation and balloon dilatation to restore biventricular circulation is gaining more popularity, with improving results over time. We report in our experience of 79 cases in 10 years the development of a sub-pulmonary membrane in 4 cases: causing significant obstruction requiring surgical excision in one case that revealed a fibrous membrane on pathology; causing mild right ventricular outflow tract obstruction in another and not yet causing obstruction in 2. On cardiac MRI, the right ventricular outflow tract and the right ventricular outflow tract/pulmonary atresia angle showed no morphological abnormalities.

Molecular analysis of dilated and left ventricular noncompaction cardiomyopathies in Egyptian children.

BACKGROUND: Paediatric cardiomyopathy is a progressive, often lethal disorder and the most common cause of heart failure in children. Despite its severe outcomes, the genetic aetiology is still poorly characterised. High-throughput sequencing offers a great opportunity for a better understanding of the genetic causes of cardiomyopathy. AIM: The current study aimed to elucidate the genetic background of cardiomyopathy in Egyptian children. METHODS: This hospital-based study involved 68 patients; 58 idiopathic primary dilated cardiomyopathy and 10 left ventricular noncompaction cardiomyopathy. Cardiomyopathy-associated genes were investigated using targeted next-generation sequencing. RESULTS: Consanguinity was positive in 53 and 70% of dilated cardiomyopathy and left ventricular noncompaction cardiomyopathy patients, respectively. Positive family history of cardiomyopathy was present in 28% of dilated cardiomyopathy and 10% of the left ventricular noncompaction cardiomyopathy patients. In 25 patients, 29 rare variants were detected; 2 likely pathogenic variants in TNNI3 and TTN and 27 variants of uncertain significance explaining 2.9% of patients. CONCLUSIONS: The low genetic detection rate suggests that novel genes or variants might underlie paediatric cardiomyopathy in Egypt, especially with the high burden of consanguinity. Being the first national and regional report, our study could be a reference for future genetic testing in Egyptian cardiomyopathy children. Genome-wide tests (whole exome/genome sequencing) might be more suitable than the targeted sequencing to investigate the primary cardiomyopathy patients. Molecular characterisation of cardiomyopathies in different ethnicities will allow for global comparative studies that could result in understanding the pathophysiology and heterogeneity of cardiomyopathies.

Early onset left ventricular remodeling in juvenile systemic lupus erythematosus; Insight from 3-dimensional speckle tracking echocardiography.

BACKGROUND: Early diagnosis and treatment of myocardial affection in patients with systemic lupus erythematosus (SLE) are crucial. OBJECTIVES: To evaluate the ventricular systolic function in juvenile-onset systemic lupus erythematosus (j-SLE) patients by 3-D speckle tracking echocardiography (3D-STE) and to determine the predictors of left ventricular (LV) dysfunction if present. METHODS: Twenty-six SLE patients without heart failure and 21 healthy controls were studied by standard echocardiogram and 3D-STE. Conventional parameters included LV ejection fraction (EF), fractional shortening (FS), and mitral annular plane systolic excursion (MAPSE). Global LV strain (GLS) and global area strain (GAS) were obtained by 3D-STE. Medical records, including diagnosis criteria, duration of disease, and SLE disease activity index (SLEDAI) were evaluated. RESULTS: The mean age was similar in patients and controls 11.42 vs 11.48 years p = 0.93. The mean duration of the disease was 1.87 ± 1.02 years and SLEDAI ranged from 0 to 9. By conventional and tissue Doppler imaging echocardiography, only MAPSE was significantly lower in SLE patients compared to controls (14.56 vs 18.46 mm, p < 0.001). By 3D speckle tracking echocardiography, GLS and GAS were significantly reduced in SLE patients compared to controls (-15.07 vs -19.9.4%, -34.6% vs -39.7%, respectively, p < 0.001). Multiple linear regression and ROC analyses indicated that the SLEDAI score was the only predictive factor for the left ventricular remodeling. CONCLUSIONS: These results indicate that early subclinical LV dysfunction occur in jSLE patients even with normal EF and SLE disease activity might be a potential driver for LV deformation.

Transcatheter closure of residual patent ductus arteriosus.

INTRODUCTION: Residual patent ductus arteriosus (rPDAs) can occur following surgical or transcatheter treatment, and are indicated for closure because of the risks of infective endarteritis and hemolysis in addition to the hemodynamic effect of the residual left-to-right shunt. METHODS: This retrospective descriptive study describes our experience at two Egyptian centers (Cairo University Children's Hospital & Tanta University Hospital) with transcatheter treatment of rPDAs, from January 2009 to October 2017. RESULTS: Twenty cases were treated: 17/20 postsurgical and 3/20 post-transcatheter, at a mean period of 13.4 ± 9.3 months from the initial procedure. The median rPDA size was 2 mm (range2-3.5 mm). Most common ductal anatomy was the conical shape. All rPDAs were successfully closed with either coils (13/20) or devices (6/20), except one case where the residual flow was within the device mesh material. Coils could be deployed from the antegrade or the retrograde approaches although the latter was associated with a higher incidence of late shunt occlusion. One case with a malpositioned device required simultaneous device and LPA stent deployment. CONCLUSION: Transcatheter closure of rPDAs is feasible in most cases, but may be technically challenging.

Genetic study of pediatric hypertrophic cardiomyopathy in Egypt.

Paediatric cardiomyopathy is a progressive and often lethal disorder and the most common cause of heart failure in children. Despite their severe outcomes, their genetic etiology is still poorly characterised. The current study aimed at uncovering the genetic background of idiopathic primary hypertrophic cardiomyopathy in a cohort of Egyptian children using targeted next-generation sequencing. The study included 24 patients (15 males and 9 females) presented to the cardiomyopathy clinic of Cairo University Children's Hospital with a median age of 2.75 (0.5-14) years. Consanguinity was positive in 62.5% of patients. A family history of hypertrophic cardiomyopathy was present in 20.8% of patients. Ten rare variants were detected in eight patients; two pathogenic variants (8.3%) in MBPC3 and MYH7, and eight variants of uncertain significance in MYBPC3, TTN, VCL, MYL2, CSRP3, and RBM20.Here, we report on the first national study in Egypt that analysed sarcomeric and non-sarcomeric variants in a cohort of idiopathic paediatric hypertrophic cardiomyopathy patients using next-generation sequencing. The current pilot study suggests that paediatric hypertrophic cardiomyopathy in Egypt might have a particular genetic background, especially with the high burden of consanguinity. Including the genetic testing in the routine diagnostic service is important for a better understanding of the pathophysiology of the disease, proper patient management, and at-risk detection. Genome-wide tests (whole exome/genome sequencing) might be better than the targeted sequencing approach to test primary hypertrophic cardiomyopathy patients in addition to its ability for the identification of novel genetic causes.

Left ventricular diastolic dysfunction without left ventricular hypertrophy in obese children and adolescents: a Tissue Doppler Imaging and Cardiac Troponin I Study.

BACKGROUND: Obesity increases the risk for various cardiovascular problems. Increase in body mass index is often an independent risk factor for the development of elevated blood pressure and clustering of various cardiovascular risk factors. OBJECTIVE: To determine early markers of left ventricular affection in obese patients before the appearance of left ventricular hypertrophy. METHODS: In this cross-sectional study, we evaluated 42 obese patients and 30 healthy controls. Their ages ranged from 6 to 19 years. Studied children were subjected to anthropometric, lipid profile, and serum Troponin I level measurements. Echocardiographic evaluation performed to assess the left ventricle included left ventricular dimension measurement using motion-mode echocardiography, based on which patients with left ventricular hypertrophy (10 patients) were eliminated, as well as conventional and tissue Doppler imaging. RESULTS: Tissue Doppler findings in the study groups showed that the ratio of transmitral early diastolic filling velocity to septal peak early diastolic myocardial velocity (E/e') was significantly higher in cases compared with controls [6.9±1.4 versus 9.0±1.6, p (Pearson's coefficient)=0.001, respectively]. The level of cardiac troponin I was significantly higher in cases compared with controls [0.14±0.39 ng/ml versus 0.01±0.01 ng/ml, p (Pearson's coefficient)=0.047, respectively] and there was a significant correlation between troponin I and transmitral early diastolic filling velocity to septal peak early diastolic myocardial velocity ratio (E/e') [R (correlation coefficient)=0.6]. CONCLUSION: Tissue Doppler Imaging and Troponin I evaluation proved useful tools to detect early affection of the left ventricle in obese patients even in the absence of left ventricular hypertrophy.

Delayed Myocardial Enhancement in Pediatric Hypertrophic Cardiomyopathy: Correlation with LV Function, Echocardiography, and Demographic Parameters.

Our aim was (1) to detect the presence of fibrosis by Cardiac magnetic resonance imaging (CMR) in the pediatric age group. (2) Correlate CMR findings with demographic data, LV function, and other echocardiographic parameters. We studied 40 pediatric patients diagnosed as HCM by echocardiography. All patients were subjected to clinical examination (in which the NYHA classification was determined for each patient), echocardiography, and CMR. CMR was done on a 1.5T Philips Achieva scanner in SSFP with delayed myocardial enhancement (DE-MRI). All demographic and functional parameters as well as pressure gradient across left ventricular outflow tract (LVOT) were correlated with the percentage of myocardial enhancement. We studied 13 female and 27 male patients from 45 days up to 18 years. The mean percentage of DE-MRI was 9.7 ± 9%. We found significant correlation between the NYHA classification and the pressure gradient across the LVOT (P = < 0.001) as well as the percentage of DE-MRI (P = 0.004). The percentage of DE-MRI showed positive correlation with LV myocardial mass index (P = 0.042). It didn't correlate with any other demographic or LV functional cardiac parameters. A good positive correlation was detected between the percentage of DE-MRI and the severity of pressure gradient across LVOT measured by echocardiography (r = 0.69 and P = <0.001). We found a significant correlation between the percentage of DE-MRI in children with HCM and the pressure gradient across LVOT, NYHA classification, and LV myocardial mass. This may help in the further management of those patients, planning for follow-up, and prognosis of the disease.