Kyriaki Papadopoulou-Legbelou

Truncated prelamin A expression in HGPS-like patients: a transcriptional study

Premature aging syndromes are rare genetic disorders mimicking clinical and molecular features of aging. A recently identified group of premature aging syndromes is linked to mutation of the LMNA gene encoding lamins A and C, and is associated with nuclear deformation and dysfunction. Hutchinson–Gilford progeria syndrome (HGPS) was the first premature aging syndrome linked to LMNA mutation and its molecular bases have been deeply investigated. It is due to a recurrent de novo mutation leading to aberrant splicing and the production of a truncated and toxic nuclear lamin A precursor (prelamin AΔ50), also called progerin. In this work and based on the literature data, we propose to distinguish two main groups of premature aging laminopathies: (1) HGPS and HGP-like syndromes, which share clinical features due to hampered processing and intranuclear toxic accumulation of prelamin A isoforms; and (2) APS (atypical progeria syndromes), due to dominant or recessive missense mutations affecting lamins A and C. Among HGPS-like patients, several deleted prelamin A transcripts (prelamin AΔ50, AΔ35 and AΔ90) have been described. The purpose of this work was to characterize those transcripts in eight patients affected with HGP-like rare syndromes. When fibroblasts were available, the relationships between the presence and ratios of these transcripts and other parameters were studied, aiming to increase our understanding of genotype–phenotype relationships in HGPS-like patients. Altogether our results evidence that progerin accumulation is the major pathogenetic mechanism responsible for HGP-like syndromes due to mutations near the donor splice site of exon 11.

Anticonvulsant hypersensitivity syndrome closely mimicking Kawasaki disease

Anticonvulsant hypersensitivity syndrome (AHS) is an acute, life-threatening, idiosyncratic drug reaction seen within 1–8 weeks after administration of an aromatic antiepileptic drug. The authors present the case of a 16-month-old boy who developed prolonged fever, a generalised pruritic rash and eosinophilia within 4 weeks after starting treatment with phenobarbital for complicated febrile seizures. He gradually fulfilled the diagnostic criteria for classical Kawasaki disease (KD), although the rash and the subsequent desquamation were atypical, he did not defervesce quickly with administration of corticosteroids and intravenous &ggr;-globulin, and he had only two suggestive cardiac features of KD—that is, perivascular echogenicity of the coronary arteries and a small pericardial effusion. Other conditions considered in the differential diagnosis were excluded by appropriate extensive serological and microbiological studies. He recovered fully. This report shows that drugs such as phenobarbital may be responsible for febrile exanthematous illnesses that closely mimic KD.

Absence of association of FCGR2A gene polymorphism rs1801274 with Kawasaki disease in Greek patients.

Kawasaki disease is an acute, febrile syndrome in infancy, characterised by vasculitis of medium-sized arteries, and affects predominantly young children. Family-based studies on Kawasaki disease supports the contribution of genetic factors in disorder manifestation. In a recent genome-wide association study, the polymorphism rs1801274 of FCGR2A [Fc fragment of immunoglobulin G, low-affinity IIa, receptor] gene has been implicated in disease pathogenesis. The aim of the present study was to explore the association of this variant, for the first time, in a group of Kawasaki-diseased patients of Greek origin. A total of 47 Kawasaki-diseased children and 50 control subjects were enrolled in the study. Polymerase chain reaction-restriction fragment length polymorphism assay was performed in rs1801274 genotyping. No association was observed between this polymorphism genotypes or alleles distribution between Kawasaki-diseased patients and controls. Furthermore, no association was revealed between this polymorphism and cardiovascular complications in Kawasaki-diseased patients. In the literature, the reported data over this polymorphism association with Kawasaki disease in Caucasian patients are contradictory. In addition, the disease shows low prevalence in the Caucasian populations. Therefore, the independent genetic association studies on rs1801274 with Kawasaki disease in various Caucasian groups increase the amount of genetic data, which could be used in a future meta-analysis, increasing the statistical power of the resultant conclusions.

Cardiac complications and immunophenotypic profile of infectious mononucleosis syndrome in children

ObjectiveTo investigate cardiac complications in infectious mononucleosis patients and to associate them with biochemical and immunological parameters, as well as with spleen ultrasound findings.DesignCross-sectional study with follow-up.SettingTertiary care pediatric unit, in the city of Thessaloniki, Greece.Participants and InterventionsTwenty-five children (15 boys, aged 1–11.6 years) suffering from infectious mononucleosis were studied during the acute phase and after 3–6 months. Cardiac evaluation comprised of electrocardiogram, echocardiogram, and measurement of creatine phosphokinase, creatine phosphokinase cardiac isoenzyme, and troponin levels. Biochemical and immunological tests included serum transaminases, serum amylase, CD3+/CD8+ T-lymphocytes subpopulation and CD4+/CD8+ T-lymphocytes ratio.ResultsDuring acute phase, all children had splenomegaly and normal serum amylase values. 17 patients had elevated serum transaminases. Percentages of CD3+/CD8+ T-lymphocytes subpopulation were elevated and CD4+/CD8+ ratio was decreased in all patients. Echocardiography revealed mild pericardial effusion in 13 patients (10/21 with Epstein-Barr infection, 3/4 with cytomegalovirus infection), but none presented with myocarditis. Four out of these 13 patients also had markedly elevated liver enzymes, 10/13 had significant splenomegaly and 12/13 presented very low CD4+/CD8+ T-lymphocytes ratio. Pericardial effusion demonstrated a statistically significant association solely with very low CD4+/CD8+ T-lymphocytes ratio (<0.5). Repetition of laboratory tests 3-6 months post-discharge detected persistent mild pericardial effusion in five patients, along with decreased CD4+/CD8+ ratio in 1/5.ConclusionsIn infectious mononucleosis syndrome, asymptomatic pericardial effusion could be associated with very low CD4+/CD8+ ratio (<0.5). Further studies would extend and confirm such an association.

Cardiac manifestations in children with inborn errors of metabolism

Need and purposeCardiac involvement is a part of many inborn errors of metabolism, but has not been systematically studied. This review focuses on studies describing cardiac manifestations of inborn errors of metabolism in childhood.MethodsTwo independent reviewers searched the topic using PubMed database. Studies published within 20 years were considered, without applying any restrictions related to study design.Despite the small number of existing systematic studies on the topic, several case series/reports were identified.ConclusionsCardiomyopathy is the most frequent heart disorder in most metabolic defects. Heart rhythm disorders are mainly encountered in mitochondrial disorders and acidemias, whereas valvular dysfunction is a prominent finding in storage disorders. Cardiac involvement in mitochondrial disorders, congenital disorders of glycosylation and acidemias usually constitute an early symptom. On the contrary, in storage disorders, heart problems are revealed in later stages during routine multisystemic evaluation, with the exception of Pompe disease. As a variety of cardiac manifestations can be found in inborn errors of metabolism, these children should be systematically screened for heart problems during their follow-up.

Dilated Cardiomyopathy as the Only Clinical Manifestation of Carnitine Transporter Deficiency

The authors present a case of carnitine transporter deficiency, which was unmasked after an episode of respiratory distress resistant to treatment with bronchodilators. Chest radiograph showed cardiomegaly; electrocardiogram showed left ventricular hypertrophy and echocardiography revealed dilated cardiomyopathy. Heart failure therapy was initiated and metabolic screening was requested, as family history was indicative of inborn errors of metabolism. Very low levels of free carnitine and carnitine esters in blood were found and genetic testing confirmed the diagnosis of carnitine transporter deficiency. After oral supplementation with L-carnitine, symptoms gradually ameliorated and heart function had fully recovered. Sequence analysis in the SLC22A5 gene revealed the missense mutation c.1319Cxa0>xa0T (p.Th440Met) in homozygous state. Homozygous c.1319Cxa0>xa0T (p.Th440Met) mutation has not been associated with a pure cardiac phenotype before.

Human herpesvirus-6 and herpes simplex virus-1 as a cause of cardiomyopathy secondary to myocarditis in children.

Kyriaki Papadopoulou-Legbelou, Maria Gogou, Paraskevi Panagopoulou, Andreas Giannopoulos and Spyridon Rammos Fourth Department of Pediatrics, Medical School, General Hospital “Papageorgiou”, Second Department of Pediatrics, Medical School, University General Hospital “AHEPA”, Aristotle University of Thessaloniki, Thessaloniki, and Department of Pediatric Cardiology, “Onassis” Cardiac Surgery Center, Athens, Greece