Comprehensive genetic screening: The prevalence of maturity-onset diabetes of the young gene variants in a population-based childhood diabetes cohort.

BACKGROUND: Maturity-onset diabetes of the young (MODY) is caused by autosomal dominant mutations in one of 13 confirmed genes. Estimates of MODY prevalence vary widely, as genetic screening is usually restricted based on clinical features, even in population studies. We aimed to determine prevalence of MODY variants in a large and unselected pediatric diabetes cohort. METHODS: MODY variants were assessed using massively parallel sequencing in the population-based diabetes cohort (n = 1363) of the sole tertiary pediatric diabetes service for Western Australia (population 2.6 million). All individuals were screened, irrespective of clinical features. MODY variants were also assessed in a control cohort (n = 993). RESULTS: DNA and signed consent were available for 821 children. Seventeen children had pathogenic/likely pathogenic variants in MODY genes, two diagnosed with type 2 diabetes, four diagnosed with antibody-negative type 1 diabetes (T1DM), three diagnosed with antibody-positive T1DM, and eight previously diagnosed with MODY. Prevalence of MODY variants in the sequenced cohort was 2.1%, compared to 0.3% of controls. CONCLUSIONS: This is the first comprehensive study of MODY variants in an unselected population-based pediatric diabetes cohort. The observed prevalence, increasing access to rapid and affordable genetic screening, and significant clinical implications suggest that genetic screening for MODY could be considered for all children with diabetes, irrespective of other clinical features.

A novel INS mutation in a family with maturity-onset diabetes of the young: Variable insulin secretion and putative mechanisms.

Insulin gene (INS) mutations cause a rare form of maturity-onset diabetes of the young (MODY), a heterogeneous group of autosomal dominant diabetes with at least 14 confirmed causative genes. Here, we describe a family with MODY due to a novel INS mutation, detected using massively parallel sequencing (MPS). The proband presented aged 11 years with mild diabetic ketoacidosis. She was negative for IA2 and GAD antibodies. She had a strong family history of diabetes affecting both her two siblings and her mother, none of whom had ketosis but who were considered to have type 1 diabetes and managed on insulin, and her maternal grandfather, who was managed for decades on sulfonylureas. Of note, her younger sister had insulin deficiency but an elevated fasting proinsulin:insulin ratio of 76% (ref 5%-30%). Sanger sequencing of HNF4A, HNF1A, and HNF1B in the proband was negative. Targeted MPS using a custom-designed amplicon panel sequenced on an Illumina MiSeq detected a heterozygous INS mutation c.277G>A (p.Glu93Lys). Sanger sequencing confirmed the variant segregated with diabetes within the family. Structural analysis of this variant suggested disruption of a critical hydrogen bond between insulin and the insulin receptor; however, the clinical picture in some individuals also suggested abnormal insulin processing and insulin deficiency. This family has a novel INS mutation and demonstrated variable insulin deficiency. MPS represents an efficient method of MODY diagnosis in families with rarer gene mutations.

Long-term outcome of insulin pump therapy in children with type 1 diabetes assessed in a large population-based case-control study.

AIMS/HYPOTHESIS: We determined the impact of insulin pump therapy on long-term glycaemic control, BMI, rate of severe hypoglycaemia and diabetic ketoacidosis (DKA) in children. METHODS: Patients on pump therapy at a single paediatric tertiary hospital were matched to patients treated by injections on the basis of age, duration of diabetes and HbA1c at the time of pump start. HbA1c, anthropometric data, episodes of severe hypoglycaemia and rates of hospitalisation for DKA were collected prospectively. RESULTS: A total of 345 patients on pump therapy were matched to controls on injections. The mean age, duration of diabetes at pump start and length of follow-up were 11.4 (± 3.5), 4.1 (± 3.0) and 3.5 (± 2.5) years, respectively. The mean HbA1c reduction in the pump cohort was 0.6% (6.6 mmol/mol). This improved HbA1c remained significant throughout the 7 years of follow-up. Pump therapy reduced severe hypoglycaemia from 14.7 to 7.2 events per 100 patient-years (p < 0.001). In contrast, severe hypoglycaemia increased in the non-pump cohort over the same period from 6.8 to 10.2 events per 100 patient-years. The rate of hospitalisation for DKA was lower in the pump cohort (2.3 vs 4.7 per 100 patient-years, p = 0.003) over the 1,160 patient-years of follow-up. CONCLUSIONS/INTERPRETATION: This is the longest and largest study of insulin pump use in children and demonstrates that pump therapy provides a sustained improvement in glycaemic control, and reductions of severe hypoglycaemia and hospitalisation for DKA compared with a matched cohort using injections.

Sterile abscess formation associated with depot leuprorelin acetate therapy for central precocious puberty.

We describe a case of an 8 year old girl with central precocious puberty. She was commenced on 3 monthly intramuscular depot Leuprorelin acetate therapy, as a result of which she developed sterile abscesses. She was converted to daily subcutaneous Leuprorelin acetate therapy with no recurrence of the abscesses. The possible mechanisms for this reaction are described in the article.

Nationally Subsidized Continuous Glucose Monitoring: A Cost-effectiveness Analysis.

OBJECTIVE: The Continuous Glucose Monitoring (CGM) Initiative recently introduced universal subsidized CGM funding for people with type 1 diabetes under 21 years of age in Australia. We thus aimed to evaluate the cost-effectiveness of this CGM Initiative based on national implementation data and project the economic impact of extending the subsidy to all age-groups. RESEARCH DESIGN AND METHODS: We used a patient-level Markov model to simulate disease progression for young people with type 1 diabetes and compared government-subsidized access to CGM with the previous user-funded system. Three years of real-world clinical input data were sourced from analysis of the Australasian Diabetes Data Network and National Diabetes Services Scheme registries. Costs were considered from the Australian health care system's perspective. An annual discount rate of 5% was applied to future costs and outcomes. Uncertainty was evaluated with probabilistic and deterministic sensitivity analyses. RESULTS: Government-subsidized CGM funding for young people with type 1 diabetes compared with a completely user-funded model resulted in an incremental cost-effectiveness ratio (ICER) of AUD 39,518 per quality-adjusted life-year (QALY) gained. Most simulations (85%) were below the commonly accepted willingness-to-pay threshold of AUD 50,000 per QALY gained in Australia. Sensitivity analyses indicated that base-case results were robust, though strongly impacted by the cost of CGM devices. Extending the CGM Initiative throughout adulthood resulted in an ICER of AUD 34,890 per QALY gained. CONCLUSIONS: Providing subsidized access to CGM for people with type 1 diabetes was found to be cost-effective compared with a completely user-funded model in Australia.

Universal Subsidized Continuous Glucose Monitoring Funding for Young People With Type 1 Diabetes: Uptake and Outcomes Over 2 Years, a Population-Based Study.

OBJECTIVE: Continuous glucose monitoring (CGM) is increasingly used in type 1 diabetes management; however, funding models vary. This study determined the uptake rate and glycemic outcomes following a change in national health policy to introduce universal subsidized CGM funding for people with type 1 diabetes aged <21 years. RESEARCH DESIGN AND METHODS: Longitudinal data from 12 months before the subsidy until 24 months after were analyzed. Measures and outcomes included age, diabetes duration, HbA1c, episodes of diabetic ketoacidosis and severe hypoglycemia, insulin regimen, CGM uptake, and percentage CGM use. Two data sources were used: the Australasian Diabetes Database Network (ADDN) registry (a prospective diabetes database) and the National Diabetes Service Scheme (NDSS) registry that includes almost all individuals with type 1 diabetes nationally. RESULTS: CGM uptake increased from 5% presubsidy to 79% after 2 years. After CGM introduction, the odds ratio (OR) of achieving the HbA1c target of <7.0% improved at 12 months (OR 2.5, P < 0.001) and was maintained at 24 months (OR 2.3, P < 0.001). The OR for suboptimal glycemic control (HbA1c ≥9.0%) decreased to 0.34 (P < 0.001) at 24 months. Of CGM users, 65% used CGM >75% of time, and had a lower HbA1c at 24 months compared with those with usage <25% (7.8 ± 1.3% vs. 8.6 ± 1.8%, respectively, P < 0.001). Diabetic ketoacidosis was also reduced in this group (incidence rate ratio 0.49, 95% CI 0.33-0.74, P < 0.001). CONCLUSIONS: Following the national subsidy, CGM use was high and associated with sustained improvement in glycemic control. This information will inform economic analyses and future policy and serve as a model of evaluation diabetes technologies.

Structural chromosome disruption of the NR3C2 gene causing pseudohypoaldosteronism type 1 presenting in infancy.

Type I pseudohypoaldosteronism (PHA1) is a rare form of mineralocorticoid resistance presenting in infancy with renal salt wasting and failure to thrive. Here, we present the case of a 6-week-old baby girl who presented with mild hyponatraemia and dehydration with a background of severe failure to thrive. At presentation, urinary sodium was not measurably increased, but plasma aldosterone and renin were increased, and continued to rise during the subsequent week. Despite high calorie feeds the infant weight gain and hyponatraemia did not improve until salt supplements were commenced. Subsequently, the karyotype was reported as 46,XX,inv (4)(q31.2q35). A search of the OMIM database for related genes at or near the inversion breakpoints, showed that the mineralocorticoid receptor gene (NR3C2) at 4q31.23 was a likely candidate. Further FISH analysis showed findings consistent with disruption of the NR3C2 gene by the proximal breakpoint (4q31.23) of the inversion. There was no evidence of deletion or duplication at or near the breakpoint. This is the first report of a structural chromosome disruption of the NR3C2 gene giving rise to the classical clinical manifestations of pseudohypoaldosteronism type 1 in an infant.

A KCNK16 mutation causing TALK-1 gain of function is associated with maturity-onset diabetes of the young.

Maturity-onset diabetes of the young (MODY) is a heterogeneous group of monogenic disorders of impaired pancreatic ß cell function. The mechanisms underlying MODY include ß cell KATP channel dysfunction (e.g., KCNJ11 [MODY13] or ABCC8 [MODY12] mutations); however, no other ß cell channelopathies have been associated with MODY to date. Here, we have identified a nonsynonymous coding variant in KCNK16 (NM_001135105: c.341T>C, p.Leu114Pro) segregating with MODY. KCNK16 is the most abundant and ß cell-restricted K+ channel transcript, encoding the two-pore-domain K+ channel TALK-1. Whole-cell K+ currents demonstrated a large gain of function with TALK-1 Leu114Pro compared with TALK-1 WT, due to greater single-channel activity. Glucose-stimulated membrane potential depolarization and Ca2+ influx were inhibited in mouse islets expressing TALK-1 Leu114Pro with less endoplasmic reticulum Ca2+ storage. TALK-1 Leu114Pro significantly blunted glucose-stimulated insulin secretion compared with TALK-1 WT in mouse and human islets. These data suggest that KCNK16 is a previously unreported gene for MODY.

Development and implementation of a logic model: Occupational stress, physical activity, and sedentary behavior in the workplace.

BACKGROUND: An increasing level of occupational stress is a major problem in the workplace that requires innovative approaches and strategies. An understudied research area pertains to the effects that physical activity performed during the workday have on occupational stress. OBJECTIVE: To determine if and how an intervention that increases physical activity and reduces sedentary behavior affects workplace stress. The population of interest are employees at a large university medical center including supportive staff, healthcare professionals, physicians, and faculty members; the study design is longitudinal; the approach is the implementation of an innovative workplace program (i.e., the Booster Break). METHODS: We present a logic model promoting physical activity and reducing sitting time during the workday as a feasible and practical strategy to cope with occupational stress. RESULTS: The logic model approach emphasizes that funding, partnerships, and incentives are inputs to implementing program activities such as Booster Break sessions, weekly meetings, social support, and personal self-monitoring. Short-term outcomes were categorized as psychosocial, goal setting, organizational, and social; intermediate outcomes were behavioral and psychosocial; and long-term outcomes were health status and physiological status. CONCLUSIONS: This study is the first known effort to outline a comprehensive intervention based on changing physical activity and sedentary behavior during the workday and the concomitant effects on occupational stress. The findings of this study can be used to develop and implement interventions at workplaces to target increases in physical activity, decreases in sedentary time, and improvements in overall employee health.

Cost-effectiveness Analysis of Routine Screening Using Massively Parallel Sequencing for Maturity-Onset Diabetes of the Young in a Pediatric Diabetes Cohort: Reduced Health System Costs and Improved Patient Quality of Life.

OBJECTIVE: Maturity-onset diabetes of the young (MODY) is an autosomal dominant form of diabetes, with multiple causative genes. Some MODY subtypes can be treated with sulfonylureas instead of insulin, improving glycemic control, complication rates, quality of life (QoL), and costs. Using massively parallel sequencing (MPS), we recently determined the prevalence of pathogenic/likely pathogenic MODY variants in an Australian pediatric diabetes cohort. Here, these data are used to estimate cost-effectiveness of using MPS for MODY in all pediatric diabetes cases compared with standard practice (sequencing limited to individuals with specific clinical features). RESEARCH DESIGN AND METHODS: A Markov decision model was developed to estimate incremental costs and quality-adjusted life-years (QALYs) of MPS screening, modeled over 30 years. We used our observed prevalence of 2.14% compared with 0.7% for standard practice, based on published data. The probabilities and utility weightings of long-term diabetes complications were based on HbA1c and estimated from published data. A series of one-way sensitivity analyses were performed using the net monetary benefit framework. RESULTS: Routine MPS screening for MODY was more effective and less costly than standard care screening, with 26 QALYs gained and 1,016,000 AUD (782,000 USD) saved per 1,000 patients. Cost of screening was fully offset within 10 years. Routine MPS screening remained dominant until MODY prevalence fell to <1.1%. CONCLUSIONS: Routine MPS screening for MODY in the pediatric population with diabetes could reduce health system costs and improve patient QoL. Our results make a compelling argument for routine genetic screening in all children with presumed type 1 diabetes mellitus.

Emotional enhancement of perceptual priming is preserved in aging and early-stage Alzheimer's disease.

Perceptual priming for emotionally-negative and neutral scenes was tested in early-stage Alzheimer's disease (AD) patients and healthy younger, middle-aged and older adults. In the study phase, participants rated the scenes for their arousal properties. In the test phase, studied and novel scenes were initially presented subliminally, and the exposure duration was gradually increased until a valence categorization was made. The difference in exposure duration required to categorize novel versus studied items was the dependent measure of priming. Aversive content increased the magnitude of priming, an effect that was preserved in healthy aging and AD. Results from an immediate recognition memory test showed that the priming effects could not be attributable to enhanced explicit memory for the aversive scenes. These findings implicate a dissociation between the modulatory effect of emotion across implicit and explicit forms of memory in aging and early-stage AD.

A genome-wide linkage analysis of dementia in the Amish.

Susceptibility genes for Alzheimer's disease are proving to be highly challenging to detect and verify. Population heterogeneity may be a significant confounding factor contributing to this difficulty. To increase the power for disease susceptibility gene detection, we conducted a genome-wide genetic linkage screen using individuals from the relatively isolated, genetically homogeneous, Amish population. Our genome linkage analysis used a 407-microsatellite-marker map (average density 7 cM) to search for autosomal genes linked to dementia in five Amish families from four Midwestern U.S. counties. Our highest two-point lod score (3.01) was observed at marker D4S1548 on chromosome 4q31. Five other regions (10q22, 3q28, 11p13, 4q28, 19p13) also demonstrated suggestive linkage with markers having two-point lod scores >2.0. While two of these regions are novel (4q31 and 11p13), the other regions lie close to regions identified in previous genome scans in other populations. Our results identify regions of the genome that may harbor genes involved in a subset of dementia patients, in particular the North American Amish community.