Intracranial calcifications simulating Aicardi-Goutières syndrome in PARS2-related mitochondrial disease.

PARS2 encodes an aminoacyl-tRNA synthetase that catalyzes the ligation of proline to mitochondrial prolyl-tRNA molecules. Diseases associated with PARS2 primarily affect the central nervous system, causing early infantile developmental epileptic encephalopathies (EIDEE; DEE75; MIM #618437) with infantile-onset neurodegeneration. Dilated cardiomyopathy has also been reported in the affected individuals. About 10 individuals to date have been described with pathogenic biallelic variants in PARS2. While many of the reported individuals succumbed to the disease in the first two decades of life, autopsy findings have not yet been reported. Here, we describe neuropathological findings in a deceased male with evidence of intracranial calcifications in the basal ganglia, thalamus, cerebellum, and white matter, similar to Aicardi-Goutières syndrome. This report describes detailed autopsy findings in a child with PARS2-related mitochondrial disease and provides plausible evidence that intracranial calcifications may be a previously unrecognized feature of this disorder.

The Many Faces of Arrhythmogenic Cardiomyopathy: An Overview.

Arrhythmogenic cardiomyopathy (AC) is a disease that involves electromechanical uncoupling of cardiomyocytes. This leads to characteristic histologic changes that ultimately lead to the arrhythmogenic clinical features of the disease. Initially thought to affect the right ventricle predominantly, more recent data show that it can affect both the ventricles or the left ventricle alone. Throughout the recent era, diagnostic modalities and criteria for AC have continued to evolve and our understanding of its clinical features in different age groups as well as the genotype to the phenotype correlations have improved. In this review, we set out to detail the epidemiology, etiologies, presentations, evaluation, and management of AC across the age continuum.

In Utero Presentation of Left Ventricular Aneurysm.

Congenital left ventricular aneurysm, pseudoaneurysm, and diverticulum are rare entities. These diagnoses can be made pre- and/or postnatally. Although these entities overlap clinically and morphologically, important distinctions can allow for accurate diagnoses. Appropriate diagnosis can be imperative for risk stratification and guidance of prenatal and postnatal management. The case described in the present report highlights a challenging case of a fetal left ventricular aneurysm, management during the prenatal and postnatal periods, and important differentiating features from a ventricular diverticulum and pseudoaneurysm.

Atypical infiltrates on endomyocardial biopsy are associated with adverse outcomes in pediatric heart transplantation.

BACKGROUND: The significance of atypical infiltrates (eosinophils or plasma cells) on endomyocardial biopsy (EMB) after pediatric heart transplant (HTx) is not known. We hypothesized that atypical infiltrates are associated with worse post-HTx outcomes. METHODS: We performed a retrospective cohort study of consecutive patients <21 years old who underwent primary HTx between 2013 and 2017. Multiorgan transplants were excluded. The presence of atypical infiltrates and burden of atypical infiltrates (rare vs predominant) on EMB were recorded. Primary outcome was a composite of cardiac allograft vasculopathy, graft failure (relisting or retransplant), or death. Presence of atypical infiltrates was evaluated: (1) overall using Cox regression with time-dependent covariates and (2) if present by 1 year post-HTx using Kaplan-Meier analysis. RESULTS: Atypical infiltrates were present in 24 out of 95 patients (25%) and were associated with a higher likelihood of reaching the composite outcome (hazard ratio (HR) 6.22, 95% confidence interval (CI) 2.60-14.89, p < 0.0001). This persisted when controlling for rejection in multivariable analysis. There was also a greater risk of the composite outcome if ≥2 nonconsecutive EMBs had atypical infiltrates (HR 11.80, 95%CI 3.17-43.84, p = 0.0002) or if atypical infiltrates were the predominant feature on EMB (HR 30.58, 95%CI 9.34-100.06, p < 0.0001). Patients with atypical infiltrates by 1-year post-HTx had a 5-year freedom from the composite outcome of 48%, compared to 90% if no atypical infiltrates had been present by this timepoint (log rank p = 0.002). CONCLUSIONS: The presence of atypical infiltrates on EMB is associated with significantly worse outcomes in children following HTx. These patients require closer follow-up to assess for developing graft dysfunction.

Arrhythmogenic cardiomyopathy is under-recognized in end-stage pediatric heart failure: A 36-year single-center experience.

BACKGROUND: Although ventricular failure is a late finding in adults with AC, we hypothesize that this is a presenting symptom in pediatric heart failure patients who undergo HT and that their ventricular arrhythmia burden could differentiate AC from other cardiomyopathies. METHODS: We performed a single-center retrospective cohort study reviewing 457 consecutive pediatric (≤18 years) HT recipients at our institution. Explanted hearts were examined to establish the primary diagnosis, based on pathologic findings. Demographic and clinical variables were compared between AC versus non-HCM cardiomyopathy cases. RESULTS: Forty-five percent (n = 205/457) had non-HCM cardiomyopathies as the underlying primary diagnosis. Ten cases (10/205 = 4.9%) were diagnosed with AC. All 10 had biventricular disease. In 8/10 patients (80%), AC diagnosis was unrecognized pre-HT. Compared with non-AC cardiomyopathies, the AC group was older at diagnosis (9.3 years vs. 4.3 years, p = .012) and transplant (11.1 years vs. 6.5 years, p = .010), had more ventricular arrhythmias (80.0% vs 32.8%, p = .003), and required more anti-arrhythmic use (80.0% vs 32.3%, p = .001). Genetic testing yielded causative pathogenic variants in all tested individuals (n = 5/5, 100%). CONCLUSION: AC is often an unrecognized cardiomyopathy pretransplant in children who undergo HT. Pediatric non-HCM phenotypes with heart failure who have a significant ventricular arrhythmia burden should be investigated for AC.

LMOD2-related dilated cardiomyopathy presenting in late infancy.

Leiomodin-2 (LMOD2) is an important regulator of the thin filament length, known to promote elongation of actin through polymerization at pointed ends. Mice with Lmod2 deficiency die around 3 weeks of age due to severe dilated cardiomyopathy (DCM), resulting from decreased heart contractility due to shorter thin filaments. To date, there have been three infants from two families reported with biallelic variants in LMOD2, presenting with perinatal onset DCM. Here, we describe a third family with a child harboring a previously described homozygous frameshift variant, c.1243_1244delCT (p.L415Vfs*108) with DCM, presenting later in infancy at 9 months of age. Family history was relevant for a sibling who died suddenly at 1 year of age after being diagnosed with cardiomegaly. LMOD2-related cardiomyopathy is a rare form of inherited cardiomyopathy resulting from thin filament length dysregulation and should be considered in genetic evaluation of newborns and infants with suspected autosomal recessive inheritance or sporadic early onset cardiomyopathy.

A Novel Large-Vessel Arteritis in SARS-CoV-2-Related Multisystem Inflammatory Syndrome in Children (MIS-C).

Multisystem inflammatory syndrome in children (MIS-C) is a newly defined condition associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The syndrome has been described as a "Kawasaki disease"-like illness and the spectrum of associated abnormalities, including vascular complications, remain to be fully defined. The novel findings of a large-vessel arteritis in this report will add to the understanding of this syndrome and its associated vascular complications.

Congenital Aortic Insufficiency From an Abnormal Left Aortic Cusp Results in Acute Coronary Syndrome.

Acute coronary syndrome (ACS) is a rare presentation in children with isolated congenital aortic insufficiency (AI). We report the case of a six-week-old previously well male who presented with an out-of-hospital cardiac arrest and was diagnosed with severe AI from a left aortic cusp anomaly resulting in ACS. The infant successfully underwent an emergent Ross operation.

Extrahepatic Nonreticuloendothelial Siderosis Is Not Specific to Gestational Alloimmune Liver Disease.

Autopsy reports of 78 stillbirths and early infant deaths (up to age 8 weeks) were reviewed to investigate the prevalence of extrahepatic nonreticuloendothelial siderosis (EHNRS) in the context of neonatal liver failure. Of these, 10 liveborns (12.8%), M:F 3:2, with mean gestational age 37.6 weeks (range: 35-39) and mean age at the time of demise 19.1 days (range: 7-42), showed significant liver injury: infection (n = 7, viral > fungal), congenital malformations (n = 2), and ischemia (n = 1). None had maternal history of gestational alloimmune liver disease (GALD) or previous fetal/neonatal death due to liver failure. Seven of 10 cases (70%) showed EHNRS: pancreas (n = 6), kidneys (n = 4), thyroid and adrenal glands (n = 3), and bronchial glands and heart (n = 2). Iron deposition was most frequent in the pancreas (60%), most diffuse in the kidneys, and seen in at least 2 organs, with pancreas and kidney being the most frequent combination. Hepatic C5b-9 expression was variable (1+ to 4+) except 1 case (100% necrosis). The duration of illness and the mean age at the time of demise tended to be higher in those with EHNRS. In summary, hepatic and EHNRS, with or without C5b-9 expression, are not specific for GALD. Other causes of liver failure should be investigated as clinically and pathologically appropriate.

A 14-year-old in heart failure with multiple cardiomyopathy variants illustrates a role for signal-to-noise analysis in gene test re-interpretation.

Variants of unknown significance in cardiomyopathic disease should be analyzed systematically based on the prevalence of the variant in the population compared to prevalence of disease, evidence that other variants in the gene are pathologic, consistency of prediction software on pathogenicity, and the current clinical consensus.

Acute humoral rejection in an infant without risk factors after heart transplantation.

Graft rejection is the most common factor that limits graft survival after transplantation. During infancy, the humoral immune system is partially suppressed and humoral rejection of a cardiac allograft has not been reported in the absence of risk factors such as prior transplantation, blood transfusions, ventricular assist devices, and elevation of panel reactive antibodies. We present a case of an infant with dilated cardiomyopathy who developed multiple episodes of acute humoral rejection after heart transplantation in the absence of risk factors.

Narrowing the FOXF1 distant enhancer region on 16q24.1 critical for ACDMPV.

BACKGROUND: Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a rare lethal lung developmental disorder caused by heterozygous point mutations or genomic deletions involving FOXF1 or its 60-kb tissue-specific enhancer region mapping 270 kb upstream of FOXF1 and involving fetal lung-expressed long non-coding RNA genes and CpG-enriched sites. Recently, we have proposed that the FOXF1 locus at 16q24.1 may be a subject of genomic imprinting. FINDINGS: Using custom-designed aCGH and Sanger sequencing, we have identified a novel de novo 104 kb genomic deletion upstream of FOXF1 in a patient with histopathologically verified full phenotype of ACDMPV. This deletion allowed us to further narrow the FOXF1 enhancer region and identify its critical 15-kb core interval, essential for lung development. This interval harbors binding sites for lung-expressed transcription factors, including GATA3, ESR1, and YY1, and is flanked by the lncRNA genes and CpG islands. Bisulfite sequencing of one of these CpG islands on the non-deleted allele showed that it is predominantly methylated on the maternal chromosome 16. CONCLUSIONS: Substantial narrowing and bisulfite sequencing of the FOXF1 enhancer region on 16q24.1 provided new insights into its regulatory function and genomic imprinting.

Pre-cannulation lung biopsy shortens ECMO course.

We describe the clinical course of an infant with respiratory failure who underwent lung biopsy prior to cannulation for undergoing extracorporeal membrane oxygenation (ECMO). Pathology revealed alveolar capillary dysplasia, and ECMO was discontinued. Rapid diagnosis allowed for closure and saved resources. We recommend considering early biopsy in infants with atypical pulmonary hypertension.

Pulmonary capillary hemangiomatosis in a neonate with congenital diaphragmatic hernia.

Pulmonary capillary hemangiomatosis (PCH) is a rare cause of pulmonary hypertension (PHTN). We present a neonate with congenital diaphragmatic hernia (CDH) and concurrent PCH. Severe PHTN was unrelenting and death occurred at 4 months. Diagnosis of PCH is challenging in the setting of CDH and portends a poor prognosis.

Expanding the genotype-phenotype correlation in subtelomeric 19p13.3 microdeletions using high resolution clinical chromosomal microarray analysis.

Structural rearrangements of chromosome 19p are rare, and their resulting phenotypic consequences are not well defined. This is the first study to report a cohort of eight patients with subtelomeric 19p13.3 microdeletions, identified using clinical chromosomal microarray analysis (CMA). The deletion sizes ranged from 0.1 to 0.86 Mb. Detailed analysis of the patients' clinical features has enabled us to define a constellation of clinical abnormalities that include growth delay, multiple congenital anomalies, global developmental delay, learning difficulties, and dysmorphic facial features. There are eight genes in the 19p13.3 region that may potentially contribute to the clinical phenotype via haploinsufficiency. Moreover, in silico genomic analysis of 19p13.3 microdeletion breakpoints revealed numerous highly repetitive sequences, suggesting LINEs/SINEs-mediated events in generating these microdeletions. Thus, subtelomeric 19p13.3 appears important for normal embryonic and childhood development. The clinical description of patients with deletions in this genomic interval will assist clinicians to identify and treat individuals with similar deletions.

Green tea extract: a potential cause of acute liver failure.

The use of herbal products has increased significantly in recent years. Because these products are not subject to regulation by the Food and Drug Administration and are often used without supervision by a healthcare provider, the indication for and consumption of these supplements is quite variable. Moreover, their use is generally regarded as safe and natural by the lay-public. Unfortunately, there has been an increase in the number of reported adverse events occurring with the use of herbal products. We present a case of acute impending liver failure in an adolescent male using a weight-loss product containing green tea extract. Our case adds to the growing concern surrounding the ingestion of green tea extract and serves to heighten healthcare provider awareness of a potential green tea extract hepatotoxicity. Despite the generally touted benefits of green tea as a whole, clinical concern regarding its use is emerging and has been linked to its concentration in multiple herbal supplements. Interestingly, the suspected harmful compounds are those previously proposed to be advantageous for weight-loss, cancer remedy, and anti-inflammatory purposes. Yet, we emphasize the need to be aware of not just green tea extract, but the importance of monitoring patient use of all dietary supplements and herbal products.

The pathological spectrum of left-ventricular hypoplasia.

Left-ventricular (LV) hypoplasia encompasses a range of LV sizes, varying from a mildly underdeveloped, but functionally adequate, chamber to the miniscule, barely perceptible LV cavity seen in hypoplastic left-heart syndrome. Associated malformations include obstructive lesions of LV inflow, outflow, and the aortic arch, often in combination. Repair of complex combinations and/or severe LV hypoplasia usually results in a single-ventricle anatomy with the right ventricle serving as the systemic ventricle. New therapeutic interventions, including fetal procedures, are expanding the spectrum of lesions and LV sizes that may be amenable to a biventricular repair. These surgical considerations place renewed emphasis on understanding the anatomical features associated with LV hypoplasia. This review details pathological features of the full spectrum of LV hypoplasia, particularly those with borderline severe hypoplasia. Primary defining lesions are described as well as additional lesions that may affect clinical symptoms, surgical repair, and long-term outcome.

A 25-year experience of endomyocardial biopsy safety in infants.

OBJECTIVES: To analyze the outcomes and risk factors associated with endomyocardial biopsy (EMB) in children less than one year of age. BACKGROUND: EMB has proven to be an integral diagnostic tool to evaluate suspected myocarditis, identify tumor histology, and provide tissue-graft surveillance after cardiac transplantation. The morbidity and mortality of EMB has been well established in the adult literature and reviewed in the general pediatric population, but there remains limited data for children in the first year of life. METHODS: We retrospectively reviewed the cardiology database at our institution to identify patients less than one year of age who underwent EMB between 1984 and 2008. Cardiac catheterization reports were reviewed for patient demographics, biopsy indication, procedural details, and complications. RESULTS: A total of 99 EMBs were performed, 49 for evaluation of suspected myocarditis, 43 for transplant rejection surveillance, 3 to identify tumor histology, and 4 for suspected endocardial fibroelastosis. Forty procedures were performed in children age < 6 months with 11 complications and 59 procedures performed in children age ≥ 6 months with four complications. In total, there were 12 EMB procedures (12.1%) with associated complications: 9 arrhythmias, 4 perforations requiring pericardiocentesis, 1 pneumothorax, and 1 death. Univariate analysis revealed a significant association between perforation and both weight <8 kg (P = 0.05) and age <6 months (P = 0.01). CONCLUSION: Endomyocardial biopsies can be performed safely in infants, although children under 6 months of age and less than 8 kg represent a high risk group and deserve special consideration due to the incidence of complications in this cohort.