Congenital hyperinsulinism of infancy (CHI) is the most common cause of hypoglycemia in newborns and infants. Several molecular mechanisms are involved in the development of CHI, but the most common genetic defects are inactivating mutations of the ABCC8 or KCNJ11 genes. The classical treatment for CHI has been pancreatectomy that eventually leads to diabetes. More recently, conservative treatment has been attempted in some cases, with encouraging results. Whether or not the patients with heterozygous ABCC8 mutations submitted to conservative treatment may spontaneously develop type 2 diabetes in the long run, is a controversial issue. Here, we report a family carrying the dominant heterozygous germ line E1506K mutation in ABCC8 associated with persistent hypoglycemia in the newborn period and diabetes in adulthood. The mutation occurred as a de novo germ line mutation in the mother of the index patient. Her hypoglycemic symptoms as a child occurred after the fourth year of life and were very mild, but she developed glucose metabolism impairment in adulthood. On the other hand, in her daughter, the clinical manifestations of the disease occurred in the neonatal period and were more severe, leading to episodes of tonic-clonic seizures that were well controlled with octreotide or diazoxide. Our data corroborate the hypothesis that the dominant E1506K ABCC8 mutation, responsible for CHI, predisposes to the development of glucose intolerance and diabetes later in life.

OBJECTIVE: The aim of this study was to establish the best cutoff values for waist circumference (WC), body mass index (BMI) and HOMA-IR (HR) to identify a cluster (> 3) of cardiovascular risk factors (CVRF) in normal glucose-tolerant (NGT) Brazilian children and adolescents. SUBJECTS AND METHODS: Cross-sectional study of 319 individuals (aged 10 to 19y) from a southern Brazilian city. Gender-specific receiver-operating characteristics (ROC) curves were constructed to assess cutoffs values of BMI (kg/m², WC (cm), and HR. RESULTS: The areas under the ROC curves to detect a cluster of CVRF were 0.92, 0.93 and 0.68 (females), and 0.93, 0.93 and 0.89 (males), for WC, BMI and HR, respectively. The cutoff values were 83.0 and 80.5 cm (WC), 22.7 and 20.4 kg/m2 (BMI), and 1.65 and 1.95 (HR), for females and males, respectively, to detect the cluster of CVRF. CONCLUSION: These values of BMI, WC-) and (HR) detected a high proportion of NGTt Brazilian children and adolescents with a cluster of CVRF.

A complex interaction of genetic and environmental factors can trigger the immune-mediated mechanism responsible for type 1 diabetes mellitus (T1DM) establishment. Environmental factors may initiate and possibly sustain, accelerate, or retard damage to β-cells. The role of environmental factors in this process has been exhaustive studied and viruses are among the most probable ones, especially enteroviruses. Improvements in enterovirus detection methods and randomized studies with patient follow-up have confirmed the importance of human enterovirus in the pathogenesis of T1DM. The genetic risk of T1DM and particular innate and acquired immune responses to enterovirus infection contribute to a tolerance to T1DM-related autoantigens. However, the frequency, mechanisms, and pathways of virally induced autoimmunity and β-cell destruction in T1DM remain to be determined. It is difficult to investigate the role of enterovirus infection in T1DM because of several concomitant mechanisms by which the virus damages pancreatic β-cells, which, consequently, may lead to T1DM establishment. Advances in molecular and genomic studies may facilitate the identification of pathways at earlier stages of autoimmunity when preventive and therapeutic approaches may be more effective.

Maternally inherited diabetes and deafness (MIDD) has been related to an A to G transition in the mitochondrial tRNA Leu (UUR) gene at the base pair 3243. This subtype of diabetes is characterized by maternal transmission, young age at onset and bilateral hearing impairment. Besides diabetes and deafness, the main diagnostic features, a wide range of multisystemic symptoms may be associated with the A3243G mutation. Organs that are most metabolically active, such as muscles, myocardium, retina, cochlea, kidney and brain are frequently affected. Gastrointestinal tract symptoms are also common in patients with mitochondrial disease and constipation and diarrhea are the most frequent manifestations. However, there are few prior reports of intestinal pseudo obstruction in MIDD patients. Here we report the case of a patient with MIDD associated with the mtDNA A3243G mutation who developed chronic intestinal pseudo obstruction, and the introduction of Coenzyme Q10 as adjunctive therapy led to a solution of the pseudo obstruction.

Enteroviruses are main candidates among environmental agents in the development of type 1 diabetes (T1D). However, the relationship between virus and the immune system response during T1D pathogenesis is heterogeneous. This is an interesting paradigm and the search for answers would help to highlight the role of viral infection in the etiology of T1D. The current data is a cross-sectional study of affected and non-affected siblings from T1D multiplex-sib families to analyze associations among T1D, genetic, islet autoantibodies and markers of innate immunity. We evaluated the prevalence of anti-virus antibodies (Coxsackie B and Echo) and its relationships with human leukocyte antigen (HLA) class II alleles, TLR expression (monocytes), serum cytokine profile and islet β cell autoantibodies in 51 individuals (40 T1D and 11 non-affected siblings) from 20 T1D multiplex-sib families and 54 healthy control subjects. The viral antibody profiles were similar among all groups, except for antibodies against CVB2, which were more prevalent in the non-affected siblings. TLR4 expression was higher in the T1D multiplex-sib family's members than in the control subjects. TLR4 expression showed a positive correlation with CBV2 antibody prevalence (rS: 0.45; P = 0.03), CXCL8 (rS: 0.65, Bergamin et al. Enterovírus, HLA, Autoimmunity, Type 1 Diabetes P = 0.002) and TNF-α (rS: 0.5, P = 0.01) serum levels in both groups of T1D multiplex-sib family. Furthermore, within these families, there was a positive correlation between HLA class II alleles associated with high risk for T1D and insulinoma-associated protein 2 autoantibody (IA-2A) positivity (odds ratio: 38.8; P = 0.021). However, the HLA protective haplotypes against T1D prevalence was higher in the non-affected than the affected siblings. This study shows that although the prevalence of viral infection is similar among healthy individuals and members from the T1D multiplex-sib families, the innate immune response is higher in the affected and in the non-affected siblings from these families than in the healthy controls. However, autoimmunity against β-islet cells and an absence of protective HLA alleles were only observed in the T1D multiplex-sib members with clinical disease, supporting the importance of the genetic background in the development of T1D and heterogeneity of the interaction between environmental factors and disease pathogenesis despite the high genetic diversity of the Brazilian population.