Characterization of HMGA2 variants expands the spectrum of Silver-Russell syndrome.

Silver-Russell syndrome (SRS) is a heterogeneous disorder characterized by intrauterine and postnatal growth retardation. HMGA2 variants are a rare cause of SRS and its functional role in human linear growth is unclear. Patients with suspected SRS negative for 11p15LOM/mUPD7 underwent whole-exome and/or targeted-genome sequencing. Mutant HMGA2 protein expression and nuclear localization were assessed. Two Hmga2-knockin mouse models were generated. Five clinical SRS patients harbored HMGA2 variants with differing functional impacts: 2 stop-gain nonsense variants (c.49G>T, c.52C>T), c.166A>G missense variant, and 2 frameshift variants (c.144delC, c.145delA) leading to an identical, extended-length protein. Phenotypic features were highly variable. Nuclear localization was reduced/absent for all variants except c.166A>G. Homozygous knockin mice recapitulating the c.166A>G variant (Hmga2K56E) exhibited a growth-restricted phenotype. An Hmga2Ter76-knockin mouse model lacked detectable full-length Hmga2 protein, similarly to patient 3 and 5 variants. These mice were infertile, with a pygmy phenotype. We report a heterogeneous group of individuals with SRS harboring variants in HMGA2 and describe the first Hmga2 missense knockin mouse model (Hmga2K56E) to our knowledge causing a growth-restricted phenotype. In patients with clinical features of SRS but negative genetic screening, HMGA2 should be included in next-generation sequencing testing approaches.

Serum hepcidin concentrations in relation to iron status in children with type 1 diabetes.

Chronic low-grade inflammation in type 1 diabetes (T1D) might increase hepcidin synthesis, possibly resulting in functional iron deficiency (FID). We hypothesized that in T1D children with FID, hepcidin concentrations are increased compared to those with normal iron status and those with absolute iron deficiency (AID). We evaluated hepcidin concentrations in T1D children in relation to iron status, and investigated whether hepcidin is useful in assessing FID. A cross-sectional study was conducted. FID was defined as elevated zinc protoporphyrin/heme ratio and/or red blood cell distribution width, and AID as low serum ferritin concentration. Post-hoc analyses with different definitions of FID were performed, using transferrin saturation and reticulocyte hemoglobin content. Serum hepcidin concentrations were measured using mass-spectrometry. The IRODIAB-study is registered at www.trialregister.nl (NTR4642). This study included 215 T1D children with a median age of 13.7 years (Q1-Q3: 10.1-16.3). The median (Q1-Q3) hepcidin concentration in patients with normal iron status was 1.8 nmol/l (0.9-3.3), in AID-patients, 0.4 nmol/l (0.4-0.4) and in FID-patients, 1.6 nmol/l (0.7-3.5). Hepcidin concentrations in FID-patients were significantly higher than in AID-patients (p < 0.001). Irrespective of FID-definition used, hepcidin concentrations did not differ between FID-patients and patients with normal iron status. This might be explained by the influence of various factors on hepcidin concentrations, and/or by differences in response of iron parameters over time. Single hepcidin measurements do not seem useful in assessing FID in T1D children. Multiple hepcidin measurements over time in future studies, however, might prove to be more useful in assessing FID in children with T1D.

[Growth failure as a symptom of inflammatory bowel disease]. / Afbuigende lengtegroeicurve bij inflammatoire darmziekte.

BACKGROUND: Growth failure can be a unique manifestation of untreated intestinal inflammation in children with inflammatory bowel disease (IBD). It can, however, be difficult to diagnose IBD in the absence of symptoms or in the presence of aspecific gastrointestinal symptoms. A delay in diagnosis is a risk factor for lower adult height. CASE DESCRIPTION: A 15--year-old boy was referred to a paediatric endocrinologist for growth failure and delayed puberty. Additional investigations were performed and he was diagnosed with Crohn's disease. CONCLUSION: IBD needs to be considered in a child presenting with growth failure and delayed puberty. A detailed medical history of any gastrointestinal symptoms should be taken. One should perform additional investigations according to the guidelines in a patient who fulfils criteria of short stature.

The influence of food order on postprandial glucose levels in children with type 1 diabetes.

OBJECTIVE: To evaluate the effect of the order of intake of carbohydrates, protein, and fat on postprandial glucose levels in children with type 1 diabetes (T1D). Our hypothesis was that postprandial glucose levels would be lower when fat and protein are consumed prior to carbohydrates, compared to a meal where all macronutrients are combined. METHODS: A randomized, open-label, within-subject crossover study was conducted. Twenty patients aged 7 to 17 years diagnosed with T1D for >1 year consumed 2 isocaloric meals (with similar composition) in random order. In 1 meal, the protein and fat part was consumed 15 minutes prior to the carbohydrates (test meal). In the other meal, all macronutrients were consumed together (standard meal). Capillary blood glucose measurements and continuous glucose monitoring system were used to assess multiple glucose levels during a 3-hour postprandial period. RESULTS: Overall, mean glucose levels were 1 mmol/L lower following the test meal compared to the standard meal (9.30 ± 3.20 vs 10.24 ± 3.35 mmol/L; P < .001). No significant difference in peak glucose was found. Glucose excursions were 1.5 and 1 mmol/L lower at 30 and 120 minutes following the test meal. A reduction in the total time period in which glucose levels exceeded 10 and 12 mmol/L of 28.7 (P = .001) and 22.3 minutes (P = .004), respectively, after the test meal was found. CONCLUSIONS: This study shows that consumption of protein and fat prior to carbohydrates results in lower postprandial glucose levels and reduced glycemic variability in children with T1D.

Sugarsquare, a Web-Based Patient Portal for Parents of a Child With Type 1 Diabetes: Multicenter Randomized Controlled Feasibility Trial.

BACKGROUND: Raising a child with type 1 diabetes (T1D) means combining the demands of the disease management with everyday parenting, which is associated with increased levels of distress. A Web-based patient portal, Sugarsquare, was developed to support parents, by providing online parent-professional communication, online peer support and online disease information. OBJECTIVE: The first aim of this study was to assess the feasibility of conducting a multicenter, randomized controlled trial in Dutch parents of a child with T1D. The second aim was to assess the feasibility of implementing Sugarsquare in clinical practice. METHODS: The parents of 105 children (N=105) with T1D below the age of 13 participated in a 6-month multicenter randomized controlled feasibility trial. They were randomly assigned to an experimental (n=54, usual care and Sugarsquare) or a control group (n=51, usual care). Attrition rates and user statistics were gathered to evaluate feasibility of the trial and implementation. To determine potential efficacy, the parenting stress index (PSI-SF) was assessed at baseline (T0) and after 6 months (T1). RESULTS: Of a potential population of parents of 445 children, 189 were willing to participate (enrollment refusal=57.5%, n=256), 142 filled in the baseline questionnaire (baseline attrition rate=25%, n=47), and 105 also filled in the questionnaire at T1 (post randomization attrition rate during follow-up=26%, n=32). As such, 24% of the potential population participated. Analysis in the experimental group (n=54) revealed a total of 32 (59%) unique users, divided into 12 (38%) frequent users, 9 (28%) incidental users, and 11 (34%) low-frequent users. Of the total of 44 professionals, 34 (77%) logged in, and 32 (73%) logged in repeatedly. Analysis of the user statistics in the experimental group further showed high practicability and integration in all users, moderate acceptability and demand in parents, and high acceptability and demand in health care professionals. Baseline parenting stress index scores were related to the parents' frequency of logging on (ρ=.282, P=.03) and page-views (ρ=.304, P=.01). No significant differences in change in parenting stress between experimental and control group were found (F3,101=.49, P=.49). CONCLUSIONS: The trial can be considered feasible, considering the average enrollment refusal rate, baseline attrition rate and postrandomization attrition rate, compared to other eHealth studies, although lower than hypothesized. Implementing Sugarsquare in clinical practice was partly feasible, given moderate demand and acceptability in parent users and lack of potential efficacy. Parents who reported higher levels of parenting stress used Sugarsquare more often than other parents, although Sugarsquare did not reduce parenting stress. These results indicate that Web-based interventions are a suitable way of providing parents of children with T1D with additional support. Future studies should determine how Sugarsquare could reduce parenting stress, for instance by adding targeted interventions. Factors potentially contributing to successful implementation are suggested. TRIAL REGISTRATION: Nederlands Trial Register Number: NTR3643; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=3643 (Archived by WebCite at http://www.webcitation.org/6qihOVCi6).