Michele Sacco

The Italian National Survey for Prader-Willi syndrome: an epidemiologic study.

Twenty‐five medical centers and the Prader–Willi Syndrome (PWS) Association collaborated on a study which attempted to identify all people with genetically confirmed diagnosis of PWS living in Italy. Investigators of the participating centers contacted PWS subjects and/or their family, filled in a specially developed form with the required data and forwarded this information by email. The study identified 425 subjects (209 males and 216 females, between the ages of 0.4–46.7). Two hundred thirty‐eight patients had del15, 104 had UPD15, 4 demonstrated a translocation affecting chromosome 15 and 79 showed a positive methylation test. There were fewer subjects found over the age of 35, probably due to the low rate of identification of older PWS patients as well as the high mortality rate. There were a greater number of male children and adolescents with PWS whilst, amongst adults, there were more females. As expected, the majority of subjects with PWS were obese, especially in adult life. Nevertheless, it is noteworthy that 26% of patients aged between 6 and 17 were normal weight. A total of 212 subjects had received GH treatment, of which 141 were still receiving therapy, while the remaining 71 had stopped. In children and adolescents (233 cases), 89 subjects had never undergone GH therapy. Eighteen PWS patients had died in the past 20 years. Obesity‐related cardiovascular and respiratory diseases were the cause of death, both during childhood and after 18 years of age. Three children died suddenly whilst undergoing GH therapy. Respiratory infection and cardiac illness were the causes of death in two cases. There was no definitive cause of death found in the third case. Overall, there was no increase in number of deaths during GH treatment, suggesting that GH administration in patients with PWS, as a group, does not increase the risk of death.

Phenotypic variability in Bartter syndrome type I

Abstract Limited phenotypic variability has been reported in patients with Bartter syndrome type I, with mutations in the Na-K-2Cl cotransporter gene (BSC). The diagnosis of this hereditary renal tubular disorder is usually made in the antenatal-neonatal period, due to the presence of polyhydramnios, premature delivery, hypokalemia, metabolic alkalosis, hypercalciuria, and nephrocalcinosis. Among nine children with hypercalciuria and nephrocalcinosis, we identified new mutations consistent with a loss of function of the mutant allele of the BSC gene in five. Three of the five cases with BSC gene mutations were unusual due to the absence of hypokalemia and metabolic alkalosis in the first years of life. The diagnosis of incomplete distal renal tubular acidosis was considered before molecular evaluation. Three additional patients with hypokalemia and hypercalciuria, but without nephrocalcinosis in the first two and with metabolic acidosis instead of alkalosis in the third, were studied. Two demonstrated the same missense mutation A555T in the BSC gene as one patient of the previous group, suggesting a single common ancestor. The third patient presented with severe hypernatremia and hyperchloremia for about 2 months, and a diagnosis of nephrogenic diabetes insipidus was hypothesized until the diagnosis of Bartter syndrome type I was established by molecular evaluation. We conclude that in some patients with Bartter syndrome type I, hypokalemia and/or metabolic alkalosis may be absent in the first years of life and persistent metabolic acidosis or hypernatremia and hyperchloremia may also be present. Molecular evaluation can definitely establish the diagnosis of atypical cases of this complex hereditary tubular disorder, which, in our experience, may exhibit phenotypic variability.

Sudden Death in Prader-Willi Syndrome during Growth Hormone Therapy

We describe a child with Prader-Willi syndrome (PWS) aged 3 years and 11 months who suddenly died 7 months after the initiation of GH therapy. The child never showed respiratory problems, but suffered from severe obesity. This case raises the question about the association between sudden death in children with PWS (with or without respiratory problems) and GH therapy, as already suspected in the recent past. We suggest that further epidemiological studies are required in order to determine more accurately the frequency of this causal connection and better understand its pathogenesis.

Metabolic syndrome in children with Prader–Willi syndrome: The effect of obesity

BACKGROUND AND AIMS Prader-Willi syndrome (PWS), the most frequent syndromic obesity, is associated with elevated morbidity and mortality in pediatric and adult ages. In PWS, the presence of metabolic syndrome (MS) has not yet been established. The aim of the study was to estimate the frequency of MS and its components in pediatric subjects according to obesity status. METHODS AND RESULTS A cross-sectional study was performed in 109 PWS children aged 2-18 years (50 obese and 59 non-obese) and in 96 simple obese controls matched for age, gender, and also for BMI with obese PWS. Obesity was defined when SDS-BMI was >2. Non-obese PWS showed significantly lower frequency of hypertension (12%) than obese PWS (32%) and obese controls (35%)(p=0.003). The same was observed for low HDL-cholesterol (3% vs 18% and 24%, p=0.001) and high triglycerides (7% vs 23% and 16%, p=0.026). Frequency of altered glucose metabolism was not different among groups (2% vs 10% and 5%), but type 2 diabetes (four cases) was present only in obese PWS. Non-obese PWS showed lower insulin and HOMA-index respect to obese PWS and obese controls (p ≤ 0.017). Overall MS frequency in PWS was 7.3%. None of the non-obese PWS showed MS compared with 16% of obese PWS and controls (p<0.001). When obesity was excluded from the analysis, a significantly lower frequency for clustering of ≥ 2 factors was still found in non-obese PWS (p=0.035). CONCLUSION Non-obese PWS showed low frequency of MS and its components, while that observed in obese PWS was very close to those of obese controls, suggesting the crucial role of obesity status. Prevention of obesity onset remains the most important goal of PWS treatment. Early identification of MS could be helpful to improve morbidity and mortality in such patients.

IL28B CC-genotype association with HLA-DQB1*0301 allele increases the prediction of spontaneous HCV RNA clearance in thalassaemic HCV-infected patients.

BACKGROUND A single nucleotide polymorphism (SNP), upstream of the IL28B gene has been recently associated with natural clearance of HCV. In a well-characterized cohort of patients with thalassaemia major exposed to the risk of acquiring HCV infection by blood transfusions, we aimed to replicate this finding and to evaluate whether combining the IL28B genotype and HLA class II alleles allow viral clearance to be accurately predicted. METHODS Of 168 patients, 130 with complete clinical history were included in the analysis. According with their HCV antibodies status 13 were defined HCV resistant, and 117 infected. Infected patients were subdivided, giving 49 with self-limiting and 68 with ongoing infection. RESULTS IL28B CC-genotype was observed in 32 patients with self-limiting and in 23 with ongoing infection (64% versus 34%; P=0.004). HLA DQB1*0301 allele was associated with viral clearance in 36 cases (73%; P<0.0001). Both DQB1*0301 and IL28B CC-genotype were found to be independent predictors of HCV clearance (OR=5.64, 95% CI 1.52-20.9 and OR=5.76, 95% CI 2.16-15.33, respectively). With the addition of DQB1*0301, the accuracy of the prediction increased from 63% to 69%. CONCLUSIONS In addition to IL28B CC-genotype, HLA DQB1*0301 helps in predicting natural clearance of HCV after acute infection.

Shprintzen-Goldberg omphalocele syndrome: a new patient with an expanded phenotype.

Shprintzen and Goldberg [ 1979 ] described a new autosomal dominant syndrome characterized by omphalocele, scoliosis, pharyngeal and laryngeal hypoplasia, mild dysmorphic face, and learning disabilities. This condition was described in a father and three daughters, one of whom died in infancy, probably of airway narrowing. Here, we report on a second observation of this syndrome in a 6‐year‐old patient. In our case, omphalocele, imperforate anus, and feeding impairment were the main clinical problems in the neonatal period. Scoliosis appeared during the fourth year of age. The facial appearance is similar to the original patients and additional clinical findings are described which expand the phenotypic spectrum.

Vascular toxicity of urea, a new âold playerâ in the pathogenesis of chronic renal failure induced cardiovascular diseases

Chronic kidney disease in children is an irreversible process that may lead to end-stage renal disease. The mortality rate in children with end-stage renal disease who receive dialysis increased dramatically in the last decade, and it is significantly higher compared with the general pediatric population. Furthermore, dialysis and transplant patients, who have developed end-stage renal disease during childhood, live respectively far less as compared with age/race-matched populations. Different reports show that cardiovascular disease is the leading cause of death in children with end-stage renal disease and in adults with childhood-onset chronic kidney disease, and that children with chronic kidney disease are in the highest risk group for the development of cardiovascular disease. Urea, which is generated in the liver during catabolism of amino acids and other nitrogenous metabolites, is normally excreted into the urine by the kidneys as rapidly as it is produced. When renal function is impaired, increasing concentrations of blood urea will steadily accumulate. For a long time, urea has been considered to have negligible toxicity. However, the finding that plasma urea is the only significant predictor of aortic plaque area fraction in an animal model of chronic renal failure -accelerated atherosclerosis, suggests that the high levels of urea found in chronic dialysis patients might play an important role in accelerated atherosclerosis in this group of patients. The aim of this review was to provide novel insights into the role played by urea in the pathogenesis of accelerated cardiovascular disease in renal failure.

Urea Memory: Transient Cell Exposure to Urea Causes Persistent Mitochondrial ROS Production and Endothelial Dysfunction

Urea at post-dialysis levels induces increased ROS in a number of cell types. The aim of this study was to determine whether urea-induced production of ROS remains elevated after urea is no longer present, and, if it does, to characterize its origin and effects. Human arterial endothelial cells were incubated with 20 mM urea for two days, and then cells were incubated for an additional two days in medium alone. Maximal ROS levels induced by initial urea continued at the same level despite urea being absent. These effects were prevented by either MnSOD expression or by Nox1/4 inhibition with GKT13781. Sustained urea-induced ROS caused a persistent reduction in mtDNA copy number and electron transport chain transcripts, a reduction in transcription of mitochondrial fusion proteins, an increase in mitochondrial fission proteins, and persistent expression of endothelial inflammatory markers. The SOD-catalase mimetic MnTBAP reversed each of these. These results suggest that persistent increases in ROS after cells are no long exposed to urea may play a major role in continued kidney damage and functional decline despite reduction of urea levels after dialysis.

Food Insecurity and Children's Rights to Adequate Nutrition in Europe

A dvocating for European children’s rights to health and well-being has characterized the wide spectrum of efforts of the European Pediatric Association-Union of National European Pediatric Societies and Associations (EPA/ UNEPSA) since its founding in 1976. These activities aim to intensify the learning processes of child health care service systems across European borders. Food security has been defined as a situation in which all community residents can obtain a safe, culturally acceptable, nutritionally adequate diet through a sustainable food system that maximizes selfreliance and social justice. Food insecurity, which refers to a lack of food access based on financial and other resources, is a never-ending issue impacting especially the health of young individuals and their development. Inadequate nutrition negatively influences children’s well-being by hampering the accomplishment of their complete physical, mental, and social comfort. The aim of this commentary is to raise pediatricians’ awareness on the emerging issue of children’s food insecurity and its risks in Europe.

P295 Optical pathway glioma and neurofibromatosis type 1

Background Neurofibromatosis Type 1 (NF1), a autosomal dominant disorder, which mainly involves Skin and nervous system: 15% of children with NF1 develops optic pathway gliomas (OPG), typically Astrocytomas pilocytic low grade, usually in the first decade of life. In one third of cases OPG occur with proptosis, visual impairment, early puberty or other disorders of hypothalamus-pituitary axis. According to current guidelines, children with NF1 should be screened frequently for visual examination and in case of visual impairment, brain MRI with the orbits analysis should performed. The current SIOP-LGG 2004 recommendations, in all cases of no-symptomatic, no-evolving glioma, provide clinical observation with close monitoring; chemotherapy is indicated only in presence of clinical signs and symptoms, or neuroimaging of progression. In the optic nerve tumours, surgery is reserved for patients with blindness, severe proptosis; chiasmatic tumours need surgery in case of exophytic tumours, with cystic component causing severe hydrocephalus or brain compression. patients and methods This is an observational study of 14 cases of OPG (5 males and 9 females) in patients with NF1, diagnosed from 1999 to 2015 c/o Paediatric Oncology Unit of our Department. We evaluated the clinical and radiological course and response to treatment of OPG. Results OPG were located exclusively to the optic nerves level in 43% of patients; 38% presented hypothalamus-optical-chiasmatic localization and 19% had chiasm or optic tracts involvment. The 57% of patients needed of chemotherapy according to the Protocol for Low Grade Glioma, cause of worsening of visual acuity, exophthalmoses or rapid increase of mass-size. The average age of chemotherapy start was 4.6 years (range 1.9 to 7 years). In only two cases there was marked reduction in the size of glioma, while in other cases the radiological picture was confirmed stationary at the stop-Therapy. Chemotherapy has allowed to stabilise the visual impairment, improving in 50% of cases the visual field. Conclusions Our data, accordingly with literature, confirmed that chemotherapeutic treatment for OPG is still unsatisfactory in most cases.