We propose that in obese patients, increased hepcidin production, at least partly leptin mediated, represents the missing link between obesity and disrupted iron metabolism.

Although the TMS6SF2 E167K variant predisposes the obese children to non-alcoholic fatty liver disease, there is an association between this variant and lower levels of cardiovascular risk factors. Overall, the data suggest differential effects of TMS6SF2 E167K variant on liver and heart health.

Cocaine- and amphetamine-regulated transcript (CART) inhibits feeding and induces the expression of c-Fos in hypothalamic areas implicated in appetite regulation. Furthermore, the CART peptide is found in neurons regulating sympathetic outflow, which in turn play an integral role in regulating body temperature and energy expenditure. The CART gene was screened by single-strand conformation polymorphism and automatic sequencing in 130 (72 girls) unrelated obese Italian children and adolescents. Their Z-scores (mean +/- SD) of relative to BMI percentiles was 3.9 +/- 1.8, and the average age at obesity onset was 4.7 +/- 2.6 years. Two previously described silent polymorphisms were found in the 3' untranslated region: an adenine deletion at position 1457 in 9 patients (allele frequency 0.035) and an A/G substitution at position 1475 in 11 patients (allele frequency 0.042). We found no difference between the obese patients heterozygous for one of these polymorphisms and those patients homozygous for the wild allele with respect to their age of obesity onset, BMI Z-scores, and leptin levels. A missense mutation of G729C resulting in the substitution of Leu with Phe at codon 34, within the NH2-terminal CART region, has been detected in the heterozygous state in a 10-year-old obese boy who has been obese since the age of 2 years. The patient belongs to a large family of obese subjects. The mutation cosegregated with the severe obesity phenotype over three generations and was not found in the control population. Resting metabolic rates were lower than expected in the propositus (-14%) and his mother (-16%), who carried the mutation. Leucine at codon 34, conserved in this position in the human and in the rat sequences, immediately precedes a couple of lysine residues that may well represent a dibasic processing site. The Leu34Phe mutation might alter the susceptibility to proteolysis of this potential processing site, likely altering the CART effect on thermogenesis and energy expenditure.

Context Acute kidney injury(AKI) and renal tubular damage(RTD), especially if complicated by acute tubular necrosis (ATN), could increase the risk of later chronic kidney disease. No prospective studies on AKI and RTD in children with type1diabetes mellitus(T1DM) onset are available. Objectives to evaluate the AKI and RTD prevalence, and their rate and timing of recovery in children with T1DM onset. Design prospective study. Settings and patients: 185children were followed up after 14days from T1DM onset. The patients who did not recover from AKI/RTD were followed-up 30 and 60days later. Main outcome measures AKI was defined according to the KDIGO criteria. RTD was defined by abnormal urinary beta-2-microglobulin and/or neutrophil gelatinase-associated lipocalin and/or tubular reabsorption of phosphate<85% and/or fractional excretion of Na(FENa)>2%. ATN was defined by RTD+AKI, prerenal-(P-)AKI by AKI+FENa<1% while acute tubular damage(ATD) by RTD without AKI. Results Prevalence of diabetic ketoacidosis(DKA) and AKI were 51.4% and 43.8% respectively. Prevalence of AKI in T1DM patients with and without DKA was 65.2% and 21.1%. 33.3% reached AKI stage2 and 66.7% of patients reached AKI stage1. RTD was evident in 136/185(73.5%) patients (32.4% showed ATN; 11.4% P-AKI; 29.7% ATD). All patients with DKA or AKI presented with RTD. The physiological and biochemical parameters of AKI and RTD were normal again in all patients. The former within 14days and the latter within 2months, respectively. Conclusions Most patients with T1DM onset may develop AKI and/or RTD, especially if presenting with DKA. Over time the physiological and biochemical parameters of AKI/RTD normalize in all patients.

This is the first demonstration that TM6SF2 E167K variant is an independent predictor of liver steatosis in chronic hepatitis C.

BACKGROUND: Melanocortin-4 receptor (MC4R) mutations have been reported as the most common single genetic cause of obesity in some populations and it has been suggested that they may be responsible for more than 4% of early-onset obesity. OBJECTIVES: To verify the presence of mutations of the MC4R coding region in children from southern Italy with early-onset obesity. SUBJECTS AND METHODS: Two-hundred and eight unrelated obese children and adolescents were included in the study. The average age at obesity onset was 4.5 AE 2.6 y. MC4R coding region was screened using both single-strand conformation polymorphism (SSCP) analysis and denaturing high-performance liquid chromatography (DHPLC). Automatic sequencing of PCR products of all individuals that showed an aberrant SSCP and=or DHPLC pattern was performed. RESULTS: One novel missense mutation and one previously described polymorphism (Vall03Ile) were identified. The missense mutation C142T, resulting in the substitution of proline with serine at codon 48, within the first MC4R transmembrane domain, was detected at the heterozygous state in a 15-y-old obese girl (body mass index (BMI) ¼ 35 kg=m 2 ) who has been obese since she was 8 y old. The mutation co-segregated with the obesity phenotype for over three generations and was not found in the control population. CONCLUSIONS: Our data show MC4R obesity causing mutations in less than 0.5% of the patients (ie 1 out of 208 patients) and therefore indicate a low prevalence of MC4R variants in the obese population from southern Italy. The specific genetic background of the Mediterranean population could make it difficult for MC4R mutations to produce an essentially polygenic trait such as common obesity, at least during childhood.

Summary Background PNPLA3 I148M polymorphism has an effect on modulation of estimated glomerular filtration rate (eGFR) in nonobese nondiabetic adults and in children with histologically confirmed nonalcoholic fatty liver disease (NAFLD). Objectives The objective of the study is to explore the impact of PNPLA3 I148M polymorphism on eGFR in children with obesity with and without NAFLD. Methods We genotyped 591 patients with obesity for PNPLA3 I148M polymorphism. Anthropometrical, biochemical, and instrumental data were collected. NAFLD was defined by the presence of ultrasound‐detected liver steatosis and/or ALT levels greater than 40 IU/L. Results Patients with NAFLD showed significantly lower eGFR levels compared with subjects without NAFLD. Children with PNPLA3 MM genotype showed lower eGFR levels compared with those with either PNPLA3 IM or II genotypes both in the presence and absence of NAFLD. A general linear model for eGFR variance, including gender, duration of obesity, PNPLA3 genotypes, HOMA, BMI‐SDS, LDL‐C, and triglycerides as covariates, confirmed an inverse association between eGFR and PNPLA3 genotype only in the presence of NAFLD. Conclusions Children with obesity and PNPLA3 MM genotype show lower eGFR levels compared with other genotypes, with a major effect of this polymorphism in the presence of NAFLD.

Background and AimsA polymorphism in adiponutrin/patatin-like phospholipase-3 gene (PNPLA3), rs738409 C->G, encoding for the I148M variant, is the strongest genetic determinant of liver fat and ALT levels in adulthood and childhood obesity. Aims of this study were i) to analyse in a large group of obese children the role of the interaction of not-genetic factors such as BMI, waist circumference (W/Hr) and insulin resistance (HOMA-IR) in exposing the association between the I148M polymorphism and ALT levels and ii) to stratify the individual risk of these children to have liver injury on the basis of this gene-environment interaction.Methods1048 Italian obese children were investigated. Anthropometric, clinical and metabolic data were collected and the PNPLA3 I148M variant genotyped.ResultsChildren carrying the 148M allele showed higher ALT and AST levels (p = 0.000006 and p = 0.0002, respectively). Relationships between BMI-SDS, HOMA-IR and W/Hr with ALT were analysed in function of the different PNPLA3 genotypes. Children 148M homozygous showed a stronger correlation between ALT and W/Hr than those carrying the other genotypes (p: 0.0045) and, therefore, 148M homozygotes with high extent of abdominal fat (W/Hr above 0.62) had the highest OR (4.9, 95% C. I. 3.2–7.8, p = 0.00001) to develop pathologic ALT.ConclusionsWe have i) showed for the first time that the magnitude of the association of PNPLA3 with liver enzymes is driven by the size of abdominal fat and ii) stratified the individual risk to develop liver damage on the basis of the interaction between the PNPLA3 genotype and abdominal fat.