Genome-wide association study and meta-analysis find that over 40 loci affect risk of type 1 diabetes

Type 1 diabetes (T1D) is a common autoimmune disorder that arises from the action of multiple genetic and environmental risk factors. We report the findings of a genome-wide association study of T1D, combined in a meta-analysis with two previously published studies. The total sample set included 7,514 cases and 9,045 reference samples. Forty-one distinct genomic locations provided evidence for association with T1D in the meta-analysis (P 10 6). After excluding previously reported associations, we further tested 27 regions in an independent set of 4,267 cases, 4,463 controls and 2,319 affected sib-pair (ASP) families. Of these, 18 regions were replicated (P 0.01; overall P 5 × 10 8) and 4 additional regions provided nominal evidence of replication (P 0.05). The many new candidate genes suggested by these results include IL10, IL19, IL20, GLIS3, CD69 and IL27

Nonketotic Hyperosmolal Diabetic Coma in a Child: Management With Low-Dose Insulin Infusion and Intracranial Pressure Monitoring

Nonketotic hyperosmolal diabetic coma, which is rare in children, is associated with a high mortality in both children and adults. We report a case of nonketotic hyperosmolal diabetic coma in a 3½-year-old child, who was successfully managed with low-dose insulin infusion and invasive intracranial pressure monitoring and recovered without sequelae. Despite severely elevated serum glucose (2,660 mg/dL) and osmolality (435 mosm/kg) levels, there was no elevation of intracranial pressure during her treatment. This case illustrates that insulin should be used cautiously and at low dose in this disease, and that intracranial pressure monitoring is of use in the management of such patients. The pathogenesis and clinical features of nonketotic hyperosmolal diabetic coma are briefly reviewed.</jats:p

Racial differences in metabolic control of children and adolescents with type I diabetes mellitus

This study evaluated racial differences in the metabolic control of children and adolescents with insulin-dependent (type I) diabetes mellitus and examined the interactive effects of race with age and sex. Data on several demographic and clinical variables were obtained for 102 black and 108 white children, including the percentage of total HbA1, age, age at diagnosis, duration of diabetes, pubertal status, insulin dose (U.kg-1.day-1), body mass index, number of clinic visits kept and missed, number of hospitalizations for diabetic ketoacidosis (DKA) for the year, and socioeconomic status (SES). Black children had higher insulin dosages (P less than 0.05) and lower SESs (P less than 0.001) than white children. HbA1 was higher in black than white children (P less than 0.01) after statistically adjusting for the effects of insulin dose, diabetes duration, and SES. With HbA1-based criteria, more black than white children were in poor and fewer in good metabolic control (P less than 0.001). Older children (greater than or equal to 13 yr) had higher HbA1 levels than younger (less than 13 yr) children (P less than 0.002), but there were no differences in HbA1 between males and females nor were there interactive effects of race, sex, and age-group. Black children were hospitalized for DKA more frequently than white children (P less than 0.04). More black than white children missed clinic visits (P less than 0.01), but they did not differ in number of visits kept. Black youths with type I diabetes mellitus are in poorer metabolic control than white youths

Designing and implementing sample and data collection for an international genetics study: The Type 1 Diabetes Genetics Consortium (T1DGC)

Background and Purpose The Type 1 Diabetes Genetics Consortium (T1DGC) is an international project whose primary aims are to: (a) discover genes that modify type 1 diabetes risk; and (b) expand upon the existing genetic resources for type 1 diabetes research. The initial goal was to collect 2500 affected sibling pair (ASP) families worldwide. Methods T1DGC was organized into four regional networks (Asia-Pacific, Europe, North America, and the United Kingdom) and a Coordinating Center. A Steering Committee, with representatives from each network, the Coordinating Center, and the funding organizations, was responsible for T1DGC operations. The Coordinating Center, with regional network representatives, developed study documents and data systems. Each network established laboratories for: DNA extraction and cell line production; human leukocyte antigen genotyping; and autoantibody measurement. Samples were tracked from the point of collection, processed at network laboratories and stored for deposit at National Institute for Diabetes and Digestive and Kidney Diseases (NIDDK) Central Repositories. Phenotypic data were collected and entered into the study database maintained by the Coordinating Center. Results T1DGC achieved its original ASP recruitment goal. In response to research design changes, the T1DGC infrastructure also recruited trios, cases, and controls. Results of genetic analyses have identified many novel regions that affect susceptibility to type 1 diabetes. T1DGC created a resource of data and samples that is accessible to the research community. Limitations Participation in T1DGC was declined by some countries due to study requirements for the processing of samples at network laboratories and/or final deposition of samples in NIDDK Central Repositories. Re-contact of participants was not included in informed consent templates, preventing collection of additional samples for functional studies. Conclusions T1DGC implemented a distributed, regional network structure to reach ASP recruitment targets. The infrastructure proved robust and flexible enough to accommodate additional recruitment. T1DGC has established significant resources that provide a basis for future discovery in the study of type 1 diabetes genetics. © The Author(s) 2010

Designing and implementing sample and data collection for an international genetics study: The Type 1 Diabetes Genetics Consortium (T1DGC)

Background and Purpose The Type 1 Diabetes Genetics Consortium (T1DGC) is an international project whose primary aims are to: (a) discover genes that modify type 1 diabetes risk; and (b) expand upon the existing genetic resources for type 1 diabetes research. The initial goal was to collect 2500 affected sibling pair (ASP) families worldwide. Methods T1DGC was organized into four regional networks (Asia-Pacific, Europe, North America, and the United Kingdom) and a Coordinating Center. A Steering Committee, with representatives from each network, the Coordinating Center, and the funding organizations, was responsible for T1DGC operations. The Coordinating Center, with regional network representatives, developed study documents and data systems. Each network established laboratories for: DNA extraction and cell line production; human leukocyte antigen genotyping; and autoantibody measurement. Samples were tracked from the point of collection, processed at network laboratories and stored for deposit at National Institute for Diabetes and Digestive and Kidney Diseases (NIDDK) Central Repositories. Phenotypic data were collected and entered into the study database maintained by the Coordinating Center. Results T1DGC achieved its original ASP recruitment goal. In response to research design changes, the T1DGC infrastructure also recruited trios, cases, and controls. Results of genetic analyses have identified many novel regions that affect susceptibility to type 1 diabetes. T1DGC created a resource of data and samples that is accessible to the research community. Limitations Participation in T1DGC was declined by some countries due to study requirements for the processing of samples at network laboratories and/or final deposition of samples in NIDDK Central Repositories. Re-contact of participants was not included in informed consent templates, preventing collection of additional samples for functional studies. Conclusions T1DGC implemented a distributed, regional network structure to reach ASP recruitment targets. The infrastructure proved robust and flexible enough to accommodate additional recruitment. T1DGC has established significant resources that provide a basis for future discovery in the study of type 1 diabetes genetics